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Sample records for plasmid-mediated tetracycline resistance

  1. The prevalence and epidemiology of plasmid-mediated penicillin and tetracycline resistance among Neisseria gonorrhoeae isolates in Guangzhou, China, 2002-2012.

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    Zheng, Heping; Wu, Xingzhong; Huang, Jinmei; Qin, Xiaolin; Xue, Yaohua; Zeng, Weiying; Lan, Yinyuan; Ou, Jiangli; Tang, Sanmei; Fang, Mingheng

    2015-10-09

    Gonococcal antimicrobial resistance is a global problem. Different resistance plasmids have emerged and spread among the isolates of Neisseria gonorrhoeae worldwide and in China. We conducted this study to monitor the plasmid-mediated penicillin and tetracycline resistance among N. gonorrhoeae isolates in Guangzhou from 2002 to 2012. Consecutive isolates of N. gonorrhoeae were collected from outpatients with gonorrhea attending the STD clinic in Guangdong Provincial Centre for Skin Diseases and STIs Control and Prevention. Penicillinase-producing N. gonorrhoeae (PPNG) isolates were analyzed by the paper acidometric method. Plasmid-mediated resistance to tetracycline in N. gonorrhoeae (TRNG) isolates was screened by the agar plate dilution method. Plasmid types were determined for TRNG and PPNG isolates using polymerase chain reaction (PCR). Minimum inhibitory concentrations (MICs) to penicillin and tetracycline were detected by the agar plate dilution. Of 1378 consecutive N. gonorrhoeae isolates, 429 PPNG and 639 TRNG isolates were identified. The prevalence of PPNG, TRNG, and PPNG/TRNG increased from 18.3 to 47.1 % (χ (2) = 31.57, p penicillin G and tetracycline persisted at high levels and the MIC90s were 32-fold higher than the resistant cutoff point over 11 years. The prevalence rates of penicillin- and tetracycline-resistant N. gonorrhoeae varied from 90.9 to 91.1 % and from 88.3 to 89.3 % during 2002 to 2012, respectively. Resistance to penicillin and tetracycline among N. gonorrhoeae isolates remained at high levels in Guangzhou. The Asian type PPNG continued to spread and Dutch type TRNG was still the dominant strain. The African type PPNG has emerged and is spreading rapidly.

  2. Plasmid mediated quinolone resistance in Enterobacteriaceae

    NARCIS (Netherlands)

    Veldman, K.T.; LS Klinisch Onderzoek Wagenaar

    2014-01-01

    This thesis describes the occurrence of Plasmid Mediated Quinolone Resistance (PMQR) in Salmonella and E. coli from The Netherlands and other European countries. Furthermore, the genetic background of these genes was characterized. Fluoroquinolones are widely used antibiotics in both human and

  3. plasmid mediated resistance in multidrug resistant bacteria isolated

    African Journals Online (AJOL)

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    PLASMID MEDIATED RESISTANCE IN MULTIDRUG RESISTANT BACTERIA. ISOLATED FROM CHILDREN WITH SUSPECTED SEPTICAEMIA IN ZARIA,. NIGERIA. AbdulAziz, Z. A.,1* Ehinmidu, J. O.,1 Adeshina, G. O.,1 Pala, Y. Y2., Yusuf, S. S2. and. Bugaje, M. A.3. 1Department of Pharmaceutics and Pharmaceutical ...

  4. Plasmid-Mediated Antimicrobial Resistance in Staphylococci and Other Firmicutes.

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    Schwarz, Stefan; Shen, Jianzhong; Wendlandt, Sarah; Fessler, Andrea T; Wang, Yang; Kadlec, Kristina; Wu, Cong-Ming

    2014-12-01

    In staphylococci and other Firmicutes, resistance to numerous classes of antimicrobial agents, which are commonly used in human and veterinary medicine, is mediated by genes that are associated with mobile genetic elements. The gene products of some of these antimicrobial resistance genes confer resistance to only specific members of a certain class of antimicrobial agents, whereas others confer resistance to the entire class or even to members of different classes of antimicrobial agents. The resistance mechanisms specified by the resistance genes fall into any of three major categories: active efflux, enzymatic inactivation, and modification/replacement/protection of the target sites of the antimicrobial agents. Among the mobile genetic elements that carry such resistance genes, plasmids play an important role as carriers of primarily plasmid-borne resistance genes, but also as vectors for nonconjugative and conjugative transposons that harbor resistance genes. Plasmids can be exchanged by horizontal gene transfer between members of the same species but also between bacteria belonging to different species and genera. Plasmids are highly flexible elements, and various mechanisms exist by which plasmids can recombine, form cointegrates, or become integrated in part or in toto into the chromosomal DNA or into other plasmids. As such, plasmids play a key role in the dissemination of antimicrobial resistance genes within the gene pool to which staphylococci and other Firmicutes have access. This chapter is intended to provide an overview of the current knowledge of plasmid-mediated antimicrobial resistance in staphylococci and other Firmicutes.

  5. Plasmid-Mediated Quinolone Resistance in Shigella flexneri Isolated From Macaques

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    Anthony J. Mannion

    2018-03-01

    Full Text Available Non-human primates (NHPs for biomedical research are commonly infected with Shigella spp. that can cause acute dysentery or chronic episodic diarrhea. These animals are often prophylactically and clinically treated with quinolone antibiotics to eradicate these possible infections. However, chromosomally- and plasmid-mediated antibiotic resistance has become an emerging concern for species in the family Enterobacteriaceae. In this study, five individual isolates of multi-drug resistant Shigella flexneri were isolated from the feces of three macaques. Antibiotic susceptibility testing confirmed resistance or decreased susceptibility to ampicillin, amoxicillin-clavulanic acid, cephalosporins, gentamicin, tetracycline, ciprofloxacin, enrofloxacin, levofloxacin, and nalidixic acid. S. flexneri isolates were susceptible to trimethoprim-sulfamethoxazole, and this drug was used to eradicate infection in two of the macaques. Plasmid DNA from all isolates was positive for the plasmid-encoded quinolone resistance gene qnrS, but not qnrA and qnrB. Conjugation and transformation of plasmid DNA from several S. flexneri isolates into antibiotic-susceptible Escherichia coli strains conferred the recipients with resistance or decreased susceptibility to quinolones and beta-lactams. Genome sequencing of two representative S. flexneri isolates identified the qnrS gene on a plasmid-like contig. These contigs showed >99% homology to plasmid sequences previously characterized from quinolone-resistant Shigella flexneri 2a and Salmonella enterica strains. Other antibiotic resistance genes and virulence factor genes were also identified in chromosome and plasmid sequences in these genomes. The findings from this study indicate macaques harbor pathogenic S. flexneri strains with chromosomally- and plasmid-encoded antibiotic resistance genes. To our knowledge, this is the first report of plasmid-mediated quinolone resistance in S. flexneri isolated from NHPs and warrants

  6. Plasmid mediated resistance in multidrug resistant bacteria isolated ...

    African Journals Online (AJOL)

    The antibiotic susceptibility testing of isolated bacteria associated with septicaemia in children were carried out using standard microbiological protocol. The MAR index for the test bacterial isolates was determined and the bacterial isolates that displayed multiple antibiotic resistance were investigated for the presence of ...

  7. Plasmid mediated colistin resistance in food animal intestinal contents detected by selective enrichment

    Science.gov (United States)

    Colistin (polymyxin E) is a cationic polypeptide antibiotic that has broad-spectrum activity against Gram-negative bacteria. It is classified as critically important in human medicine for treating hard-to-treat multi-drug resistant infections. Recently a plasmid-mediated colistin resistance gene (mc...

  8. Prevalence of plasmid-mediated quinolone resistance determinants among oxyiminocephalosporin-resistant Enterobacteriaceae in Argentina

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    Giovanna Rincon Cruz

    2013-11-01

    Full Text Available High quinolone resistance rates were observed among oxyiminocephalosporin-resistant enterobacteria. In the present study, we searched for the prevalence of plasmid-mediated quinolone resistance (PMQR genes within the 55 oxyiminocephalosporin-resistant enterobacteria collected in a previous survey. The main PMQR determinants were aac(6'-Ib-cr and qnrB, which had prevalence rates of 42.4% and 33.3%, respectively. The aac(6'-Ib-cr gene was more frequently found in CTX-M-15-producing isolates, while qnrB was homogeneously distributed among all CTX-M producers.

  9. Plasmid-mediated quinolone resistance in Salmonella serotypes isolated from chicken carcasses in Turkey

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    Zafer Ata

    2014-01-01

    Full Text Available Quinolones have been extensively used for treatment of a variety of invasive and systemic infections of salmonellosis. Widespread use of these agents has been associated with the emergence and dissemination of quinolone-resistant pathogens. The quinolone resistance and plasmid-mediated quinolone resistance determinants (qnrA, qnrB, qnrS and aac(6’-Ib-cr of 85 Salmonella isolates from chicken carcasses were investigated in this study. Isolates were serotyped according to the Kauffman-White-Le Minor scheme, and broth microdilution method was used to determine quinolone resistance. Plasmid-mediated quinolone resistance genes were investigated by real-time PCR and positive results were confirmed by sequencing. Among the Salmonella isolates, 30/85 (35% and 18/85 (21% were found to be resistant to enrofloxacin (MIC ≥ 2 mg/ml, and danofloxacin (MIC ≥ 2 mg/ml, respectively. All the isolates were negative for qnrA, qnrB and aac(6’-Ib-cr genes, nevertheless 2% (S. Brandenburg and S. Dabou were positive for qnrS (qnrS1 determinant. This study is the first and unique investigating the plasmid- mediated quinolone resistance determinants of Salmonella isolated from chicken carcasses in Turkey.

  10. Plasmid-mediated quinolone resistance; interactions between human, animal and environmental ecologies

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    Laurent ePOIREL

    2012-02-01

    Full Text Available Resistance to quinolones and fluoroquinolones is being increasingly reported among human but also veterinary isolates during the last two to three decades, very likely as a consequence of the large clinical usage of those antibiotics. Even if the principle mechanisms of resistance to quinolones are chromosome-encoded, due to modifications of molecular targets (DNA gyrase and topoisomerase IV, decreased outer-membrane permeability (porin defect and overexpression of naturally-occurring efflux, the emergence of plasmid-mediated quinolone resistance (PMQR has been reported since 1998. Although these PMQR determinants confer low-level resistance to quinolones and/or fluoroquinolones, they are a favorable background for selection of additional chromosome-encoded quinolone resistance mechanisms. Different transferable mechanisms have been identified, corresponding to the production of Qnr proteins, of the aminoglycoside acetyltransferase AAC(6’-Ib-cr, or of the QepA-type or OqxAB-type efflux pumps. Qnr proteins protect target enzymes (DNA gyrase and type IV topoisomerase from quinolone inhibition (mostly nalidixic acid. The AAC(6’-Ib-cr determinant acetylates several fluoroquinolones, such as norfloxacin and ciprofloxacin. Finally, the QepA and OqxAB efflux pumps extrude fluoroquinolones from the bacterial cell. A series of studies have identified the environment to be a reservoir of PMQR genes, with farm animals and aquatic habitats being significantly involved. In addition, the origin of the qnr genes has been identified, corresponding to the waterborne species Shewanella sp. Altogether, the recent observations suggest that the aquatic environment might constitute the original source of PMQR genes, that would secondly spread among animal or human isolates.

  11. Identification of a Plasmid-Mediated Quinolone Resistance Gene in Salmonella Isolates from Texas Dairy Farm Environmental Samples.

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    Cummings, K J; Rodriguez-Rivera, L D; Norman, K N; Ohta, N; Scott, H M

    2017-06-01

    A recent increase in plasmid-mediated quinolone resistance (PMQR) has been detected among Salmonella isolated from humans in the United States, and it is necessary to determine the sources of human infection. We had previously isolated Salmonella from dairy farm environmental samples collected in Texas, and isolates were tested for anti-microbial susceptibility. Two isolates, serotyped as Salmonella Muenster, showed the discordant pattern of nalidixic acid susceptibility and intermediate susceptibility to ciprofloxacin. For this project, whole-genome sequencing of both isolates was performed to detect genes associated with quinolone resistance. The plasmid-mediated qnrB19 gene and IncR plasmid type were identified in both isolates. To our knowledge, this is the first report of PMQR in Salmonella isolated from food animals or agricultural environments in the United States. © 2016 Blackwell Verlag GmbH.

  12. Plasmid Mediated Antibiotic and Heavy Metal Resistance in Bacillus Strains Isolated From Soils in Rize, Turkey

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    Elif SEVİM

    2015-09-01

    Full Text Available Fifteen Bacillus strains which were isolated from soil samples were examined for resistance to 17 different antibiotics (ampicillin, methicillin, erythromycin, norfloxacin, cephalotine, gentamycin, ciprofloxacin, streptomycin, tobramycin, chloramphenicol, trimethoprim-sulfamethoxazole, tetracycline, vancomycin, oxacilin, neomycin, kanamycin and, novabiocin and to 10 different heavy metals (copper, lead, cobalt, chrome, iron, mercury, zinc, nickel, manganese and, cadmium and for the presence of plasmid DNA. A total of eleven strains (67% were resistant to at least one antibiotic. The most common resistance was observed against methicillin and oxacillin. The most resistance strains were found as Bacillus sp. B3 and Bacillus sp. B11. High heavy metal resistance against copper, chromium, zinc, iron and nickel was detected, but mercury and cobalt resistance was not detected, except for 3 strains (B3, B11, and B12 which showed mercury resistance. It has been determined that seven Bacillus strains have plasmids. The isolated plasmids were transformed into the Bacillus subtilis W168 and it was shown that heavy metal and antibiotic resistance determinants were carried on these plasmids. These results showed that there was a correlation between plasmid content and resistance for both antibiotic and heavy metal resistance

  13. Seawater is a reservoir of multi-resistant Escherichia coli, including strains hosting plasmid-mediated quinolones resistance and extended-spectrum beta-lactamases genes.

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    Alves, Marta S; Pereira, Anabela; Araújo, Susana M; Castro, Bruno B; Correia, António C M; Henriques, Isabel

    2014-01-01

    The aim of this study was to examine antibiotic resistance (AR) dissemination in coastal water, considering the contribution of different sources of fecal contamination. Samples were collected in Berlenga, an uninhabited island classified as Natural Reserve and visited by tourists for aquatic recreational activities. To achieve our aim, AR in Escherichia coli isolates from coastal water was compared to AR in isolates from two sources of fecal contamination: human-derived sewage and seagull feces. Isolation of E. coli was done on Chromocult agar. Based on genetic typing 414 strains were established. Distribution of E. coli phylogenetic groups was similar among isolates of all sources. Resistances to streptomycin, tetracycline, cephalothin, and amoxicillin were the most frequent. Higher rates of AR were found among seawater and feces isolates, except for last-line antibiotics used in human medicine. Multi-resistance rates in isolates from sewage and seagull feces (29 and 32%) were lower than in isolates from seawater (39%). Seawater AR profiles were similar to those from seagull feces and differed significantly from sewage AR profiles. Nucleotide sequences matching resistance genes bla TEM, sul1, sul2, tet(A), and tet(B), were present in isolates of all sources. Genes conferring resistance to 3rd generation cephalosporins were detected in seawater (bla CTX-M-1 and bla SHV-12) and seagull feces (bla CMY-2). Plasmid-mediated determinants of resistance to quinolones were found: qnrS1 in all sources and qnrB19 in seawater and seagull feces. Our results show that seawater is a relevant reservoir of AR and that seagulls are an efficient vehicle to spread human-associated bacteria and resistance genes. The E. coli resistome recaptured from Berlenga coastal water was mainly modulated by seagulls-derived fecal pollution. The repertoire of resistance genes covers antibiotics critically important for humans, a potential risk for human health.

  14. Seawater is a reservoir of multi-resistant Escherichia coli, including strains hosting plasmid-mediated quinolones resistance and extended-spectrum beta-lactamases genes

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    Marta S. Alves

    2014-08-01

    Full Text Available The aim of this study was to examine antibiotic resistance (AR dissemination in coastal water, considering the contribution of different sources of faecal contamination. Samples were collected in Berlenga, an uninhabited island classified as Natural Reserve and visited by tourists for aquatic recreational activities. To achieve our aim, AR in Escherichia coli isolates from coastal water was compared to AR in isolates from two sources of faecal contamination: human-derived sewage and seagull faeces. Isolation of E. coli was done on Chromocult agar. Based on genetic typing 414 strains were established. Distribution of E. coli phylogenetic groups was similar among isolates of all sources. Resistances to streptomycin, tetracycline, cephalothin and amoxicillin were the most frequent. Higher rates of AR were found among seawater and faeces isolates, except for last-line antibiotics used in human medicine. Multi-resistance rates in isolates from sewage and seagull faeces (29% and 32% were lower than in isolates from seawater (39%. Seawater AR profiles were similar to those from seagull faeces and differed significantly from sewage AR profiles. Nucleotide sequences matching resistance genes blaTEM, sul1, sul2, tet(A and tet(B, were present in isolates of all sources. Genes conferring resistance to 3rd generation cephalosporins were detected in seawater (blaCTX-M-1 and blaSHV-12 and seagull faeces (blaCMY-2. Plasmid-mediated determinants of resistance to quinolones were found: qnrS1 in all sources and qnrB19 in seawater and seagull faeces. Our results show that seawater is a relevant reservoir of AR and that seagulls are an efficient vehicle to spread human-associated bacteria and resistance genes. The E. coli resistome recaptured from Berlenga coastal water was mainly modulated by seagulls-derived faecal pollution. The repertoire of resistance genes covers antibiotics critically important for humans, a potential risk for human health.

  15. Substrate analog interaction with MCR-1 offers insight into the rising threat of the plasmid-mediated transferable colistin resistance.

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    Wei, Pengcheng; Song, Guangji; Shi, Mengyang; Zhou, Yafei; Liu, Yang; Lei, Jun; Chen, Peng; Yin, Lei

    2018-02-01

    Colistin is considered a last-resort antibiotic against most gram-negative bacteria. Recent discoveries of a plasmid-mediated, transferable mobilized colistin-resistance gene ( mcr-1) on all continents have heralded the imminent emergence of pan-drug-resistant superbacteria. The inner-membrane protein MCR-1 can catalyze the transfer of phosphoethanolamine (PEA) to lipid A, resulting in colistin resistance. However, little is known about the mechanism, and few drugs exist to address this issue. We present crystal structures revealing the MCR-1 catalytic domain (cMCR-1) as a monozinc metalloprotein with ethanolamine (ETA) and d-glucose, respectively, thus highlighting 2 possible substrate-binding pockets in the MCR-1-catalyzed PEA transfer reaction. Mutation of the residues involved in ETA and d-glucose binding impairs colistin resistance in recombinant Escherichia coli containing full-length MCR-1. Partial analogs of the substrate are used for cocrystallization with cMCR-1, providing valuable information about the family of PEA transferases. One of the analogs, ETA, causes clear inhibition of polymyxin B resistance, highlighting its potential for drug development. These data demonstrate the crucial role of the PEA- and lipid A-binding pockets and provide novel insights into the structure-based mechanisms, important drug-target hot spots, and a drug template for further drug development to combat the urgent, rising threat of MCR-1-mediated antibiotic resistance.-Wei, P., Song, G., Shi, M., Zhou, Y., Liu, Y., Lei, J., Chen, P., Yin, L. Substrate analog interaction with MCR-1 offers insight into the rising threat of the plasmid-mediated transferable colistin resistance.

  16. Multiplex PCR for detection of plasmid-mediated colistin resistance determinants, mcr-1, mcr-2, mcr-3, mcr-4 and mcr-5 for surveillance purposes

    DEFF Research Database (Denmark)

    Rebelo, Ana Rita; Bortolaia, Valeria; Kjeldgaard, Jette S.

    2018-01-01

    Background and aim: Plasmid-mediated colistin resistance mechanisms have been identified worldwide in the past years. A multiplex polymerase chain reaction (PCR) protocol for detection of all currently known transferable colistin resistance genes (mcr-1 to mcr-5, and variants) in Enterobacteriace...

  17. Detection of mcr-1 encoding plasmid-mediated colistin-resistant Escherichia coli isolates from human bloodstream infection and imported chicken meat, Denmark 2015

    DEFF Research Database (Denmark)

    Hasman, H.; Hammerum, A. M.; Hansen, F.

    2015-01-01

    The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131...

  18. Plasmid-Mediated Resistance in Enterobacteriaceae Changing Landscape and Implications for Therapy

    NARCIS (Netherlands)

    Schultsz, Constance; Geerlings, Suzanne

    2012-01-01

    Antimicrobial resistance is increasing worldwide, and pathogenic microorganism's that are resistant to all available antimicrobial agents are increasingly reported. Emerging plasmid-encoded extended-spectrum beta-lactamases (ESBLs) and carbapenemases are increasingly reported worldwide.

  19. Emergence of Plasmid-Mediated Fosfomycin-Resistance Genes among Escherichia coli Isolates, France.

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    Benzerara, Yahia; Gallah, Salah; Hommeril, Baptiste; Genel, Nathalie; Decré, Dominique; Rottman, Martin; Arlet, Guillaume

    2017-09-01

    FosA, a glutathione S-transferase that inactivates fosfomycin, has been reported as the cause of enzymatic resistance to fosfomycin. We show that multiple lineages of FosA-producing extended spectrum β-lactamase Escherichia coli have circulated in France since 2012, potentially reducing the efficacy of fosfomycin in treating infections with antimicrobial drug-resistant gram-negative bacilli.

  20. Plasmid-Mediated Antibiotic Resistance and Virulence in Gram-negatives: the Klebsiella pneumoniae Paradigm.

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    Ramirez, Maria S; Traglia, German M; Lin, David L; Tran, Tung; Tolmasky, Marcelo E

    Plasmids harbor genes coding for specific functions including virulence factors and antibiotic resistance that permit bacteria to survive the hostile environment found in the host and resist treatment. Together with other genetic elements such as integrons and transposons, and using a variety of mechanisms, plasmids participate in the dissemination of these traits resulting in the virtual elimination of barriers among different kinds of bacteria. In this article we review the current information about physiology and role in virulence and antibiotic resistance of plasmids from the gram-negative opportunistic pathogen Klebsiella pneumoniae . This bacterium has acquired multidrug resistance and is the causative agent of serious communityand hospital-acquired infections. It is also included in the recently defined ESKAPE group of bacteria that cause most of US hospital infections.

  1. Molecular processes as basis for plasmid-mediated bacterial UV-light resistance and mutagenesis

    International Nuclear Information System (INIS)

    Aleshkin, G.I.; Brukhanskij, G.V.; Skavronskaya, A.G.

    1985-01-01

    The increase of UV-resistance and UV-induced mutagenesis by lambda 1 pint intmid as well as molecular-genetic mechanisms of plasmid participation in reparation and DNA replication and its degradation after UV-irradiation in plasmid cells on pKM101 plasmid model have been investigated. Data testifying to the necessity of intmid integration in chromosome as obligatory stage of intmid participation in increasing UV-resistance of bacterial cells are obtained. It has been found that intmid raises UV-resistance of cells and increases respectively the UV-induced reverants efficiency. On the basis of the experiment data the conclusion is drawn that the intmid capacity to raise UV-resistance and, possibly, mutagenesis is bound not only with its integration into chromosome but also with pol A + chromosome replication by dependendent imtmid replication complex. It is shown that pKM101 plasmid ensures functioning in E coli cells of inducible, chloroamphenicol-resistant DNA replication, highly resistant to UV-light harmful effect and that the volume of excision reparation in E. coli cells carrying pKM101 plasmid is increased as compared with the volume of reparation in plasmid legs cells. The combination of the data obtained gives grounds to the authors to assume that inducible replication, inducible reparation of DNA and inducible decrease of DNA degradation determined by pKM101 plasmid may serve as recA + lexA + basis dependent increase of UV-resistance and mutagenesis and that these processes provide the possibility of functioning of integrative replication mechanism of plasmid participation in ensuring UV-resistance and mutagenesis of plants

  2. Cloning in Streptococcus lactis of plasmid-mediated UV resistance and effect on prophage stability

    International Nuclear Information System (INIS)

    Chopin, M.C.; Chopin, A.; Rouault, A.; Simon, D.

    1986-01-01

    Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains

  3. Occurrence of Extended-Spectrum β-Lactamases, Plasmid-Mediated Quinolone Resistance, and Disinfectant Resistance Genes in Escherichia coli Isolated from Ready-To-Eat Meat Products

    DEFF Research Database (Denmark)

    Li, Lili; Ye, Lei; Kromann, Sofie

    2017-01-01

    There are growing concerns about the coselection of resistance against antibiotics and disinfectants in bacterial pathogens. The aim of this study was to characterize the antimicrobial susceptibility profiles, the prevalence of extended-spectrum β-lactamases (ESBLs), plasmid-mediated quinolone...... resistance genes (PMQRs), and quaternary ammonium compound resistance genes (QACs) in Escherichia coli isolated from ready-to-eat (RTE) meat products obtained in Guangzhou, China, and to determine whether these genes were colocalized in the isolates. A total of 64 E. coli isolates were obtained from 720 RTE...... isolates from RTE meat products. The E. coli isolates with multiple antimicrobial resistance genes may transmit to humans through food chain and thus require further investigation and increased awareness....

  4. Bacterial Resistance to the Tetracyclines and Antimicrobial ...

    African Journals Online (AJOL)

    Optimizing of tetracycline antibiotics dosing and duration in human and animal healthcare and food production might help minimize the emergence of resistance in some situations. New approaches to antimicrobial chemotherapy are needed if we are to survive the increasing rates of tetracycline antibiotic resistance ...

  5. Toxicity of tetracyclines and tetracycline degradation products to environmentally relevant bacteria, including selected tetracycline-resistant bacteria

    DEFF Research Database (Denmark)

    Halling-Sørensen, B.; Sengeløv, G.; Tjørnelund, J.

    2002-01-01

    Tetracyclines used in veterinary therapy invariably will find their way as parent compound and degradation products to the agricultural field. Major degradation products formed due to the limited stability of parent tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in aqueous...... at the same concentration level as tetracycline, chlortetracycline, and oxytetracycline on both the sludge and the tetracycline-sensitive soil bacteria. Further, both 5a,6-anhydrotetracychne and 5a,6-anhydrochlortetracycline had potency on tetracycline-resistant bacteria supporting a mode of action different...

  6. The presence of plasmid-mediated resistance genes among uropathogenes isolated from diabetic and non-diabetic patients with chronic pyelonephritis

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    O.I. Chub

    2014-10-01

    Full Text Available Increased multidrug resistance of extended-spectrum beta-lactamases (ESBLs compromises the efficacy of treatment of urinary tract infections. The objective of this study is to determine the prevalence of ESBL-producing uropathogens from patients with chronic pyelonephritis (CP and to evaluate the risk factors of these types of infections. Screening for the presence of plasmid-mediated ESBL was performed by polymerase chain reaction. Out of 105 patients, 22 (20.9% revealed strains with resistance genes: 11 (36.7%, 11 (36.7% and 8 (26.7% were identified to carry bla(TEM, bla(SHV and bla(CTX-M beta-lactamase genes, respectively. We have demonstrated that prevalence of the resistance among patients with CP combined with type 2 DM was 31.3%, while among patients with CP without type 2 DM was 27.4%; however the difference between these groups was not significant. The main factors related with appearance of plasmid-mediated resistance genes were age range above 55 years, Chronic Kidney Disease stage ІІІ and ІV, in-patient treatment history, history of using antibiotics last year. Isolation and detection of ESBL-producing strains are essential fоr the sеlection оf the mоst effеctive antibiоtic for the empiric trеatment.

  7. Novel Ambler class A beta-lactamase LAP-1 and its association with the plasmid-mediated quinolone resistance determinant QnrS1.

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    Poirel, Laurent; Cattoir, Vincent; Soares, Ana; Soussy, Claude-James; Nordmann, Patrice

    2007-02-01

    The plasmid-mediated quinolone resistance determinant QnrS1 was identified in non-clonally related Enterobacter cloacae isolates in association with a transferable narrow-spectrum beta-lactam resistance marker. Cloning experiments allowed the identification of a novel Ambler class A beta-lactamase, named LAP-1. It shares 62 and 61% amino acid identity with the most closely related beta-lactamases, TEM-1 and SHV-1, respectively. It has a narrow-spectrum hydrolysis of beta-lactams and is strongly inhibited by clavulanic acid and sulbactam and, to a lesser extent, by tazobactam. Association of the blaLAP-1 gene with the qnrS1 gene was identified in E. cloacae isolates from France and Vietnam. These genes were plasmid located and associated with similar insertion sequences but were not associated with sul1-type class 1 integrons, as opposed to the qnrA genes.

  8. Prevalence and characterisation of plasmid-mediated quinolone resistance and mutations in the gyrase and topoisomerase IV genes among Shigella isolates from Henan, China, between 2001 and 2008.

    Science.gov (United States)

    Yang, Haiyan; Duan, Guangcai; Zhu, Jingyuan; Zhang, Weidong; Xi, Yuanlin; Fan, Qingtang

    2013-08-01

    A total of 293 Shigella isolates were isolated from patients with diarrhoea in four villages of Henan, China. This study investigated the prevalence of the plasmid-mediated quinolone resistance (PMQR) genes qnrA, qnrB, qnrS, qepA and aac(6')-Ib-cr and compared the polymorphic quinolone resistance-determining regions (QRDRs) of gyrA, gyrB, parC and parE. Of the isolates, 292 were found to be resistant to nalidixic acid and pipemidic acid, whereas 77 were resistant to ciprofloxacin (resistance rate of 26.3%). Resistance of the Shigella isolates to ciprofloxacin significantly increased from 2001 to 2008 (PShigella isolates are common in China. This study found that there was a significant increase in mutation rates of the QRDR and the resistant rates to ciprofloxacin. Other mechanisms may be present in the isolates that also contribute to their resistance to ciprofloxacin. Copyright © 2013 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

  9. Prevalence and characteristics of extended-spectrum β-lactamase and plasmid-mediated fluoroquinolone resistance genes in Escherichia coli isolated from chickens in Anhui province, China.

    Directory of Open Access Journals (Sweden)

    Lin Li

    Full Text Available The aim of this study was to characterize the prevalence of extended-spectrum β-lactamase (ESBL genes and plasmid-mediated fluoroquinolone resistance (PMQR determinants in 202 Escherichia coli isolates from chickens in Anhui Province, China, and to determine whether ESBL and PMQR genes co-localized in the isolates. Antimicrobial susceptibility for 12 antimicrobials was determined by broth microdilution. Polymerase chain reactions (PCRs, DNA sequencing, and pulsed field gel electrophoresis (PFGE were employed to characterize the molecular basis for β-lactam and fluoroquinolone resistance. High rates of antimicrobial resistance were observed, 147 out of the 202 (72.8% isolates were resistant to at least 6 antimicrobial agents and 28 (13.9% of the isolates were resistant to at least 10 antimicrobials. The prevalence of blaCTX-M, blaTEM-1 and blaTEM-206 genes was 19.8%, 24.3% and 11.9%, respectively. Seventy-five out of the 202 (37.1% isolates possessed a plasmid-mediated quinolone resistance determinant in the form of qnrS (n = 21; this determinant occurred occasionally in combination with aac(6'-1b-cr (n = 65. Coexistence of ESBL and/or PMQR genes was identified in 31 of the isolates. Two E. coli isolates carried blaTEM-1, blaCTX-M and qnrS, while two others carried blaCTX-M, qnrS and aac(6'-1b-cr. In addition, blaTEM-1, qnrS and aac(6'-1b-cr were co-located in two other E. coli isolates. PFGE analysis showed that these isolates were not clonally related and were genetically diverse. To the best of our knowledge, this study is the first to describe detection of TEM-206-producing E. coli in farmed chickens, and the presence of blaTEM-206, qnrS and aac(6'-1b-cr in one of the isolates.

  10. Comparison of two DNA microarrays for detection of plasmid-mediated antimicrobial resistance and virulence factor genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae.

    LENUS (Irish Health Repository)

    Walsh, Fiona

    2010-06-01

    A DNA microarray was developed to detect plasmid-mediated antimicrobial resistance (AR) and virulence factor (VF) genes in clinical isolates of Enterobacteriaceae and non-Enterobacteriaceae. The array was validated with the following bacterial species: Escherichiacoli (n=17); Klebsiellapneumoniae (n=3); Enterobacter spp. (n=6); Acinetobacter genospecies 3 (n=1); Acinetobacterbaumannii (n=1); Pseudomonasaeruginosa (n=2); and Stenotrophomonasmaltophilia (n=2). The AR gene profiles of these isolates were identified by polymerase chain reaction (PCR). The DNA microarray consisted of 155 and 133 AR and VF gene probes, respectively. Results were compared with the commercially available Identibac AMR-ve Array Tube. Hybridisation results indicated that there was excellent correlation between PCR and array results for AR and VF genes. Genes conferring resistance to each antibiotic class were identified by the DNA array. Unusual resistance genes were also identified, such as bla(SHV-5) in a bla(OXA-23)-positive carbapenem-resistant A. baumannii. The phylogenetic group of each E. coli isolate was verified by the array. These data demonstrate that it is possible to screen simultaneously for all important classes of mobile AR and VF genes in Enterobacteriaceae and non-Enterobacteriaceae whilst also assigning a correct phylogenetic group to E. coli isolates. Therefore, it is feasible to test clinical Gram-negative bacteria for all known AR genes and to provide important information regarding pathogenicity simultaneously.

  11. High Prevalence of Plasmid-Mediated Quinolone Resistance and IncQ Plasmids Carrying qnrS2 Gene in Bacteria from Rivers near Hospitals and Aquaculture in China

    OpenAIRE

    Wen, Yanping; Pu, Xiaoying; Zheng, Wei; Hu, Guang

    2016-01-01

    Effluents from hospital and aquaculture are considered important sources of quinolone resistance. However, little information is available on the impact of this effluent on nearby rivers. In this study, 188 ciprofloxacin-resistant bacterial isolates obtained from rivers near hospitals and aquaculture were screened for plasmid-mediated quinolone resistance (PMQR) genes. Species identification, antibiotic susceptibility testing, and PMQR gene transferability assessment were conducted for PMQR-p...

  12. Plasmid-mediated resistance to thrombin-induced platelet microbicidal protein in staphylococci: role of the qacA locus.

    Science.gov (United States)

    Kupferwasser, L I; Skurray, R A; Brown, M H; Firth, N; Yeaman, M R; Bayer, A S

    1999-10-01

    Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide released from rabbit platelets following thrombin stimulation. In vitro resistance to this peptide among strains of Staphylococcus aureus correlates with the survival advantage of such strains at sites of endothelial damage in humans as well as in experimental endovascular infections. The mechanisms involved in the phenotypic resistance of S. aureus to tPMP-1 are not fully delineated. The plasmid-encoded staphylococcal gene qacA mediates multidrug resistance to multiple organic cations via a proton motive force-dependent efflux pump. We studied whether the qacA gene might also confer resistance to cationic tPMP-1. Staphylococcal plasmids encoding qacA were found to confer resistance to tPMP-1 in an otherwise susceptible parental strain. Deletions which removed the region containing the qacA gene in the S. aureus multiresistance plasmid pSK1 abolished tPMP-1 resistance. Resistance to tPMP-1 in the qacA-bearing strains was inoculum independent but peptide concentration dependent, with the level of resistance decreasing at higher peptide concentrations for a given inoculum. There was no apparent cross-resistance in qacA-bearing strains to other endogenous cationic antimicrobial peptides which are structurally distinct from tPMP-1, including human neutrophil defensin 1, protamine, or the staphylococcal lantibiotics pep5 and nisin. These data demonstrate that the staphylococcal multidrug resistance gene qacA also mediates in vitro resistance to cationic tPMP-1.

  13. Plasmid-Mediated Resistance to Thrombin-Induced Platelet Microbicidal Protein in Staphylococci: Role of the qacA Locus

    OpenAIRE

    Kupferwasser, Leon Iri; Skurray, Ronald A.; Brown, Melissa H.; Firth, Neville; Yeaman, Michael R.; Bayer, Arnold S.

    1999-01-01

    Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide released from rabbit platelets following thrombin stimulation. In vitro resistance to this peptide among strains of Staphylococcus aureus correlates with the survival advantage of such strains at sites of endothelial damage in humans as well as in experimental endovascular infections. The mechanisms involved in the phenotypic resistance of S. aureus to tPMP-1 are not fully delineated. The plasmid-encoded st...

  14. Plasmid-mediated AmpC-type beta-lactamase isolated from Klebsiella pneumoniae confers resistance to broad-spectrum beta-lactams, including moxalactam.

    Science.gov (United States)

    Horii, T; Arakawa, Y; Ohta, M; Ichiyama, S; Wacharotayankun, R; Kato, N

    1993-01-01

    Klebsiella pneumoniae NU2936 was isolated from a patient and was found to produce a plasmid-encoded beta-lactamase (MOX-1) which conferred resistance to broad spectrum beta-lactams, including moxalactam, flomoxef, ceftizoxime, cefotaxime, and ceftazidime. Resistance could be transferred from K. pneumoniae NU2936 to Escherichia coli CSH2 by conjugation with a transfer frequency of 5 x 10(-7). The structural gene of MOX-1 (blaMOX-1) was cloned and expressed in E. coli HB101. The MIC of moxalactam for E. coli HB101 producing MOX-1 was > 512 micrograms/ml. The apparent molecular mass and pI of this enzyme were calculated to be 38 kDa and 8.9, respectively. Hg2+ and Cu2+ failed to block enzyme activity, and the presence of EDTA in the reaction buffer did not reduce the enzyme activity. However, clavulanate and cloxacillin, serine beta-lactamase inhibitors, inhibited the enzyme activity competitively (Kis = 5.60 and 0.35 microM, respectively). The kinetic study of MOX-1 suggested that it effectively hydrolyzed broad-spectrum beta-lactams. A hybridization study confirmed that blaMOX-1 is encoded on a large resident plasmid (pRMOX1; 180 kb) of strain NU2936. By deletion analysis, the functional region was localized within a 1.2-kb region of the plasmid. By amino acid sequencing, 18 of 33 amino acid residues at the N terminus of MOX-1 were found to be identical to those of Pseudomonas aeruginosa AmpC. These findings suggest that MOX-1 is a plasmid-mediated AmpC-type beta-lactamase that provides enteric bacteria resistance to broad-spectrum beta-lactams, including moxalactam. Images PMID:8517725

  15. Analysis of plasmid-mediated quinolone resistance genes in clinical isolates of the tribe Proteeae from Argentina: First report of qnrD in the Americas.

    Science.gov (United States)

    Albornoz, Ezequiel; Lucero, Celeste; Romero, Genara; Rapoport, Melina; Guerriero, Leonor; Andres, Patricia; Galas, Marcelo; Corso, Alejandra; Petroni, Alejandro

    2014-12-01

    To analyse the occurrence and prevalence of plasmid-mediated quinolone resistance (PMQR) genes in the tribe Proteeae, 81 isolates (65 Proteus spp., 12 Morganella morganii and 4 Providencia stuartii) consecutively collected in 66 hospitals belonging to the WHONET-Argentina Resistance Surveillance Network were studied. Of the 81 isolates, 50 (62%) were susceptible to quinolones [43/65 (66%) Proteus spp. and 7/12 (58%) M. morganii). The remaining 31 isolates (22 Proteus spp., 5 M. morganii and all P. stuartii) showed high-level resistance to nalidixic acid (NAL) and decreased susceptibility or resistance to ciprofloxacin. All NAL-resistant isolates harboured mutations associated with quinolone resistance (MAQRs) in both gyrA (S83I/R) and parC (S80I/R), and some also had MAQRs in gyrB (S464Y/F). The unique PMQR gene detected was qnrD, which was found in 2/81 isolates (Proteus mirabilis Q1084 and Proteus vulgaris Q5169), giving a prevalence of 2.5% in Proteeae. These two isolates were from different geographical regions and both harboured MAQRs in gyrA and parC. The qnrD genes were located on the related plasmids pEAD1-1 (2683bp) and pEAD1-2 (2669bp). Plasmid pEAD1-1 was 100% identical to pCGH15 and differed in only three nucleotides from pDIJ09-518a, which were previously found in clinical isolates of P. mirabilis (China) and Providencia rettgeri (France), respectively, whilst pEAD1-2 was not previously described. The extended-spectrum β-lactamase CTX-M-2 was found in 27% (22/81) of the isolates and was significantly associated with quinolone resistance but not with qnrD (only P. mirabilis Q1084 expressed CTX-M-2). This is the first report of qnrD in the Americas. Copyright © 2014 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  16. Prevalence of Smqnr and plasmid-mediated quinolone resistance determinants in clinical isolates of Stenotrophomonas maltophilia from Japan: novel variants of Smqnr

    Directory of Open Access Journals (Sweden)

    H. Kanamori

    2015-09-01

    Full Text Available Stenotrophomonas maltophilia is an important pathogen in healthcare-associated infections. S. maltophilia may contain Smqnr, a quinolone resistance gene encoding the pentapeptide repeat protein, which confers low-level quinolone resistance upon expression in a heterologous host. We investigated the prevalence of Smqnr and plasmid-mediated quinolone resistance (PMQR determinants in S. maltophilia isolates from Japan. A total of 181 consecutive and nonduplicate clinical isolates of S. maltophilia were collected from four areas of Japan. The antimicrobial susceptibility profiles for these strains were determined. PCR was conducted for Smqnr and PMQR genes, including qnrA, qnrB, qnrC, qnrS, aac(6′-Ib and qepA. PCR products for Smqnr and aac(6′-Ib were sequenced. For the S. maltophilia isolates containing Smqnr, pulsed-field gel electrophoresis (PFGE was performed using XbaI. Resistance rates to ceftazidime, levofloxacin, trimethoprim–sulfamethoxazole, chloramphenicol and minocycline were 67.4%, 6.1%, 17.7%, 8.8% and 0%, respectively. The minimum inhibitory concentration required to inhibit the growth of 50% and 90% of organisms were 0.5 and 2 mg/L for moxifloxacin but 1 and 4 mg/L for levofloxacin, respectively. Smqnr was detected in 104 of the 181 S. maltophilia isolates (57.5%, and the most frequent was Smqnr6, followed by Smqnr8 and Smqnr11. Eleven novel variants from Smqnr48 to Smqnr58 were detected. The 24 Smqnr-containing S. maltophilia isolates were typed by PFGE and divided into 21 unique types. Nine S. maltophilia isolates (5.0% carried aac(6′-Ib-cr. No qnr or qepA genes were detected. This study describes a high prevalence of Smqnr and novel variants of Smqnr among S. maltophilia from Japan. Continuous antimicrobial surveillance and further molecular epidemiological studies on quinolone resistance in S. maltophilia are needed.

  17. Class 1 integrons and plasmid-mediated multiple resistance genes of the Campylobacter species from pediatric patient of a university hospital in Taiwan.

    Science.gov (United States)

    Chang, Yi-Chih; Tien, Ni; Yang, Jai-Sing; Lu, Chi-Cheng; Tsai, Fuu-Jen; Huang, Tsurng-Juhn; Wang, I-Kuan

    2017-01-01

    The Campylobacter species usually causes infection between humans and livestock interaction via livestock breeding. The studies of the Campylobacter species thus far in all clinical isolates were to show the many kinds of antibiotic phenomenon that were produced. Their integrons cause the induction of antibiotic resistance between bacterial species in the Campylobacter species. The bacterial strains from the diarrhea of pediatric patient which isolated by China Medical University Hospital storage bank. These isolates were identified by MALDI-TOF mass spectrometry. The anti-microbial susceptibility test showed that Campylobacter species resistant to cefepime, streptomycin, tobramycin and trimethoprim/sulfamethoxazole (all C. jejuni and C. coli isolates), ampicillin (89% of C. jejuni ; 75% of C. coli ), cefotaxime (78% of C. jejuni ; 100% of C. coli ), nalidixic acid (78% of C. jejuni ; 100% of C. coli ), tetracycline (89% of C. jejuni ; 25% C. coli ), ciprofloxacin (67% of C. jejuni ; 50% C. coli ), kanamycin (33% of C. jejuni ; 75% C. coli ) and the C. fetus isolate resisted to ampicillin, cefotaxime, nalidixic acid, tetracycline, ciprofloxacin, kanamycin by disc-diffusion method. The effect for ciprofloxacin and tetracycline of the Campylobacter species was tested using an E-test. The tet, erm , and integron genes were detected by PCR assay. According to the sequencing analysis (type I: dfr12 - gcuF - aadA2 genes and type II: dfrA7 gene), the cassette type was identified. The most common gene cassette type (type I: 9 C. jejuni and 2 C. coli isolates; type II: 1 C. coli isolates) was found in 12 class I integrase-positive isolates. Our results suggested an important information in the latency of Campylobacter species with resistance genes, and irrational antimicrobial use should be concerned.

  18. Extended-Spectrum-Beta-Lactamases, AmpC Beta-Lactamases and Plasmid Mediated Quinolone Resistance in Klebsiella spp. from Companion Animals in Italy

    DEFF Research Database (Denmark)

    Donati, Valentina; Feltrin, Fabiola; Hendriksen, Rene S.

    2014-01-01

    also for the aac(6')-Ib-cr gene. All Klebsiella isolates showed multiresistance towards aminoglycosides, sulfonamides, tetracyclines, trimethoprim and amphenicols, mediated by strA/B, aadA2, aadB, ant (2")-Ia, aac(6')-Ib, sul, tet, dfr and cat genes in various combinations. The emergence in pets...... of multidrug-resistant Klebsiella with ESBL, AmpC and PMQR determinants, poses further and serious challenges in companion animal therapy and raise concerns for possible bidirectional transmission between pets and humans, especially at household level....

  19. Investigation of the Genetic Basis of Tetracycline Resistance in ...

    African Journals Online (AJOL)

    Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching. Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was.

  20. Plasmid-mediated AmpC beta-lactamase-producing Escherichia coli causing urinary tract infection in the Auckland community likely to be resistant to commonly prescribed antimicrobials.

    Science.gov (United States)

    Drinkovic, Dragana; Morris, Arthur J; Dyet, Kristin; Bakker, Sarah; Heffernan, Helen

    2015-03-13

    To estimate the prevalence and characterise plasmid-mediated AmpC beta-lactamase (PMACBL)- producing Escherichia coli in the Auckland community. All cefoxitin non-susceptible (NS) E. coli identified at the two Auckland community laboratories between 1 January and 31 August 2011 were referred to ESR for boronic acid double-disc synergy testing, to detect the production of AmpC beta-lactamase, and polymerase chain reaction (PCR) to identify the presence of PMACBL genes. PMACBL-producing isolates were typed using pulsed-field gel electrophoresis (PFGE), and PCR was used to determine their phylogenetic group and to identify multilocus sequence type (ST)131. Antimicrobial susceptibility testing and detection of extended-spectrum beta-lactamases (ESBLs) were performed according to the Clinical and Laboratory Standards Institute recommendations. 101 (51%) and 74 (37%) of 200 non-duplicate cefoxitin-NS E. coli were PMACBL producers or assumed hyper-producers of chromosomal AmpC beta-lactamase, respectively. The prevalence of PMACBL-producing E. coli was 0.4%. PMACBL-producing E. coli were significantly less susceptible to norfloxacin, trimethoprim and nitrofurantoin than E. coli that produced neither a PMACBL nor an ESBL. Very few (4%) PMACBL-producing E. coli co-produced an ESBL. Most (88%) of the PMACBL-producing isolates had a CMY-2-like PMACBL. The PMACBL-producing E. coli isolates were diverse based on their PFGE profiles, 44% belonged to phylogenetic group D, and only four were ST131. 100 of the 101 PMACBL-producing E. coli were cultured from urine, and were causing urinary tract infection (UTI) in the majority of patients. The median patient age was 56 years and most (94%) of the patients were women. A greater proportion of patients with community-acquired UTI caused by PMACBL-producing E. coli received a beta-lactam antimicrobial than patients with community-acquired UTI caused by other non-AmpC, non-ESBL-producing E. coli. Thirty-six (43%) patients with community

  1. Tetracyclines and tetracycline resistance in agricultural soils: microcosm and field studies.

    NARCIS (Netherlands)

    Schmitt, Heike; Stoob, Krispin; Hamscher, Gerd; Smit, Eric; Seinen, Willem

    2006-01-01

    The influence of the use of antibiotics on the prevalence of resistance genes in the environment is still poorly understood. We studied the diversity of tetracycline and sulfonamide resistance genes as influenced by fertilization with pig manure in soil microcosms and at two field locations. Manure

  2. Tetracycline consumption and occurrence of tetracycline resistance in Salmonella typhimurium phage types from Danish pigs

    DEFF Research Database (Denmark)

    Emborg, Hanne-Dorthe; Vigre, Håkan; Jensen, Vibeke Frøkjær

    2007-01-01

    more than doubled at the national level from 12,000-13,000 kg of active compound in 1996-1998 to 29,000 kg of active compound in 2004. Instead, tetracycline-resistant S. Typhimurium phage types became more prevalent. This suggests that the spread of already established or new resistant clones, rather......The aims of the present study were to investigate at the farm-owner level the effect of prescribed tetracycline consumption in pigs and different Salmonella Typhimurium phage types on the probability that the S. Typhimurium was resistant to tetracycline. In this study, 1,307 isolates were included......, originating from 877 farm owners, and data were analyzed using logistic regression. The analysis showed that both the S. Typhimurium phage type (p type...

  3. Tetracycline

    Science.gov (United States)

    ... infections caused by bacteria including pneumonia and other respiratory tract infections; ; certain infections of skin, eye, lymphatic, ... tetracycline with food, especially dairy products such as milk, yogurt, cheese, and ice cream. Follow the directions ...

  4. Association Between Tetracycline Consumption and Tetracycline Resistance in Escherichia coli from Healthy Danish Slaughter Pigs

    DEFF Research Database (Denmark)

    Vieira, Antonio; Houe, Hans; Wegener, Henrik Caspar

    2009-01-01

    It has been recognized that exposure to antimicrobial agents can exert a selective pressure for the emergence of antimicrobial resistance. The objective of this study was to investigate an association between the probability of isolating a tetracycline-resistant Escherichia coli isolate from the ...... this study, we can infer that tetracycline usage, the time span between last treatment and sampling date, together with herd size and the proportion of animals being treated in a herd, increase the probability of obtaining a resistant isolate.......It has been recognized that exposure to antimicrobial agents can exert a selective pressure for the emergence of antimicrobial resistance. The objective of this study was to investigate an association between the probability of isolating a tetracycline-resistant Escherichia coli isolate from...... the intestinal tract of healthy pigs and patterns of tetracycline Consumption in the herds of origin, together with other risk factors. Data oil antimicrobial resistance, antimicrobial consumption, and pig herd demographics were obtained from different Danish surveillance programs. Descriptive statistics were...

  5. International collaborative study on the occurrence of plasmid-mediated quinolone resistance in Salmonella enterica and Escherichia coli isolated from animals, humans, food and the environment in 13 European countries

    DEFF Research Database (Denmark)

    Veldman, Kees; Cavaco, Lina; Mevius, Dik

    2011-01-01

    OBJECTIVES: This study was initiated to collect retrospective information on the occurrence of plasmid-mediated quinolone resistance (PMQR) in Salmonella enterica and Escherichia coli isolates in Europe and to identify the responsible genes. METHODS: Databases of national reference laboratories...... containing MIC values for Salmonella and E. coli isolated between 1994 and 2009 in animals, humans, food and the environment from 13 European countries were screened for isolates exhibiting a defined quinolone resistance phenotype, i.e. reduced susceptibility to fluoroquinolones and nalidixic acid. PCR...... isolate. No qnrC or qepA genes were detected in either Salmonella or E. coli. CONCLUSIONS: This study shows the occurrence and dissemination of PMQR genes in Salmonella and E. coli in Europe with a defined quinolone resistance phenotype. We also report the first detection of qnrD in Salmonella collected...

  6. Tetracyclines and tetracycline resistance in agricultural soils: microcosm and field studies.

    OpenAIRE

    Schmitt, Heike; Stoob, Krispin; Hamscher, Gerd; Smit, Eric; Seinen, Willem

    2006-01-01

    The influence of the use of antibiotics on the prevalence of resistance genes in the environment is still poorly understood. We studied the diversity of tetracycline and sulfonamide resistance genes as influenced by fertilization with pig manure in soil microcosms and at two field locations. Manure contained a high diversity of resistance genes, regardless of whether it stemmed from a farm operation with low or regular use of antibiotics. In the microcosm soils, the influence of fertilization...

  7. Comparison of metals and tetracycline as selective agents for development of tetracycline resistant bacterial communities in agricultural soil

    DEFF Research Database (Denmark)

    Song, Jianxiao; Rensing, Christopher; Holm, Peter Engelund

    2017-01-01

    Environmental selection of antibiotic resistance may be caused by either antibiotic residues or coselecting agents. Using a strictly controlled experimental design, we compared the ability of metals (Cu or Zn) and tetracycline to (co)select for tetracycline resistance in bacterial communities. Soil...... microcosms were established by amending agricultural soil with known levels of Cu, Zn, or tetracycline known to represent commonly used metals and antibiotics for pig farming. Soil bacterial growth dynamics and bacterial community-level tetracycline resistance were determined using the [(3)H......]leucine incorporation technique, whereas soil Cu, Zn, and tetracycline exposure were quantified by a panel of whole-cell bacterial bioreporters. Tetracycline resistance increased significantly in soils containing environmentally relevant levels of Cu (≥365 mg kg(-1)) and Zn (≥264 mg kg(-1)) but not in soil spiked...

  8. Tetracycline residues and tetracycline resistance genes in groundwater impacted by swine production facilities

    Science.gov (United States)

    Mackie, R.I.; Koike, S.; Krapac, I.; Chee-Sanford, J.; Maxwell, Susan; Aminov, R.I.

    2006-01-01

    Antibiotics are used at therapeutic levels to treat disease; at slightly lower levels as prophylactics; and at low, subtherapeutic levels for growth promotion and improvement of feed efficiency. Over 88% of swine producers in the United States gave antimicrobials to grower/finisher pigs in feed as a growth promoter in 2000. It is estimated that ca. 75% of antibiotics are not absorbed by animals and are excreted in urine and feces. The extensive use of antibiotics in swine production has resulted in antibiotic resistance in many intestinal bacteria, which are also excreted in swine feces, resulting in dissemination of resistance genes into the environment.To assess the impact of manure management on groundwater quality, groundwater samples have been collected near two swine confinement facilities that use lagoons for manure storage and treatment. Several key contaminant indicators-including inorganic ions, antibiotics, and antibiotic resistance genes-were analyzed in groundwater collected from the monitoring wells. Chloride, ammonium, potassium, and sodium were predominant inorganic constituents in the manure samples and served as indicators of groundwater contamination. Based on these analyses, shallow groundwater has been impacted by lagoon seepage at both sites. Liquid chromatography-mass spectroscopy (LC-MS) was used to measure the dissolved concentrations of tetracycline, chlortetracycline, and oxytetracycline in groundwater and manure. Although tetracyclines were regularly used at both facilities, they were infrequently detected in manure samples and then at relatively trace concentrations. Concentrations of all tetracyclines and their breakdown products in the groundwater sampled were generally less than 0.5 ??g/L.Bacterial tetracycline resistance genes served as distinct genotypic markers to indicate the dissemination and mobility of antibiotic resistance genes that originated from the lagoons. Applying PCR to genomic DNA extracted from the lagoon and

  9. Characterization of Plasmid-Mediated Quinolone Resistance Determinants in High-Level Quinolone-Resistant Enterobacteriaceae Isolates from the Community: First Report of qnrD Gene in Algeria.

    Science.gov (United States)

    Yanat, Betitera; Machuca, Jesús; Díaz-De-Alba, Paula; Mezhoud, Halima; Touati, Abdelaziz; Pascual, Álvaro; Rodríguez-Martínez, José-Manuel

    2017-01-01

    The objective was to assess the prevalence of plasmid-mediated quinolone resistance (PMQR)-producing isolates in a collection of quinolone-resistant Enterobacteriaceae of community origin isolated in Bejaia, Algeria. A total of 141 nalidixic acid-resistant Enterobacteriaceae community isolates were collected in Bejaia (Northern Algeria) and screened for PMQR genes using polymerase chain reaction (PCR). For PMQR-positive strains, antimicrobial susceptibility testing was performed by broth microdilution and disk diffusion. Mutations in the quinolone resistance-determining regions of the target genes, gyrA and parC, were detected with a PCR-based method and sequencing. Southern blotting, conjugation and transformation assays and molecular typing by pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing were also performed. The prevalence of PMQR-producing Enterobacteriaceae isolates was 13.5% (19/141); 11 of these isolates produced Aac(6')-Ib-cr and 8 were qnr-positive (4 qnrB1-like, 2 qnrS1-like, and 2 qnrD1-like), including the association with aac(6')-Ib-cr gene in three cases. PMQR gene transfer by conjugation was successful in 6 of 19 isolates tested. PFGE revealed that most of the PMQR-positive Escherichia coli isolates were unrelated, except for two groups comprising two and four isolates, respectively, including the virulent multidrug-resistant clone E. coli ST131 that were clonally related. Our findings indicate that PMQR determinants are prevalent in Enterobacteriaceae isolates from the community studied. We describe the first report of the qnrD gene in Algeria.

  10. Antibiotic-Resistant Extended Spectrum ß-Lactamase- and Plasmid-Mediated AmpC-Producing Enterobacteriaceae Isolated from Retail Food Products and the Pearl River in Guangzhou, China

    Science.gov (United States)

    Ye, Qinghua; Wu, Qingping; Zhang, Shuhong; Zhang, Jumei; Yang, Guangzhu; Wang, Huixian; Huang, Jiahui; Chen, Mongtong; Xue, Liang; Wang, Juan

    2017-01-01

    We conducted a survey in 2015 to evaluate the presence of extended spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC-producing Enterobacteriaceae in retail food and water of the Pearl River in Guangzhou, China, as well as their antibiotic resistance profiles. Samples (88 fresh food samples and 43 water samples) from eight different districts were analyzed by direct plating and after enrichment. Multidrug-resistant strains were found in 41.7 and 43.4% of food and water samples, respectively. ESBLs were found in 3.4 and 11.6% of food and water samples, respectively, and AmpC producers were found in 13.6 and 16.3% of food and water samples, respectively. Molecular characterization revealed the domination of blaCTX−Mgenes; plasmidic AmpC was of the type DHA-1 both in food and water samples. Thirteen of Fifty one β-lactamase-producing positive isolates were detected to be transconjugants, which readily received the β-lactamase genes conferring resistance to β-lactam antibiotics as well as some non-β-lactam antibiotics. These findings provide evidence that retail food and the river water may be considered as reservoirs for the dissemination of β-lactam antibiotics, and these resistance genes could readily be transmitted to humans through the food chain and water. PMID:28217112

  11. Trueperella pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China: Tetracycline susceptibility and tetracycline-resistance gene distribution.

    Science.gov (United States)

    Zhang, Dexian; Zhao, Jingcui; Wang, Qiuxia; Liu, Yaochuan; Tian, Chunlian; Zhao, Yujun; Yu, Lihui; Liu, Mingchun

    2017-04-01

    Trueperella pyogenes plays a crucial role in endometritis pathogenesis and is also associated with many infections, including metritis, mastitis, arthritis and liver abscessation, in many domestic animals. In this study, we investigated the prevalence of tetracycline resistance in T. pyogenes isolated from dairy cows with endometritis in Inner Mongolia, China, and we assessed tetracycline-resistance gene distribution among the isolates. Our results indicated that 68.7% and 62.5% of the isolates were resistant to tetracycline and doxycycline, respectively, and the rate of resistance to metacycline was 18.8%. The tetracycline resistance gene tetK was present in all isolates (n = 32), whereas the tetM gene was identified in 12.5% and 9.4% of the isolates, in the chromosome and plasmid, respectively. Strains carrying tetW were also common in the chromosome and plasmid, with abundances of 53.1% and 46.9%, respectively. However, tetO and otrA were absent in all isolates. The resistance phenotype analysis indicated that 6.3% of strains were susceptible to all tetracyclines, while 3.1% showed resistance to all tetracyclines. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Sub-inhibitory concentrations of heavy metals facilitate the horizontal transfer of plasmid-mediated antibiotic resistance genes in water environment.

    Science.gov (United States)

    Zhang, Ye; Gu, April Z; Cen, Tianyu; Li, Xiangyang; He, Miao; Li, Dan; Chen, Jianmin

    2018-06-01

    Although widespread antibiotic resistance has been mostly attributed to the selective pressure generated by overuse and misuse of antibiotics, recent growing evidence suggests that chemicals other than antibiotics, such as certain metals, can also select and stimulate antibiotic resistance via both co-resistance and cross-resistance mechanisms. For instance, tetL, merE, and oprD genes are resistant to both antibiotics and metals. However, the potential de novo resistance induced by heavy metals at environmentally-relevant low concentrations (much below theminimum inhibitory concentrations [MICs], also referred as sub-inhibitory) has hardly been explored. This study investigated and revealed that heavy metals, namely Cu(II), Ag(I), Cr(VI), and Zn(II), at environmentally-relevant and sub-inhibitory concentrations, promoted conjugative transfer of antibiotic resistance genes (ARGs) between E. coli strains. The mechanisms of this phenomenon were further explored, which involved intracellular reactive oxygen species (ROS) formation, SOS response, increased cell membrane permeability, and altered expression of conjugation-relevant genes. These findings suggest that sub-inhibitory levels of heavy metals that widely present in various environments contribute to the resistance phenomena via facilitating horizontal transfer of ARGs. This study provides evidence from multiple aspects implicating the ecological effect of low levels of heavy metals on antibiotic resistance dissemination and highlights the urgency of strengthening efficacious policy and technology to control metal pollutants in the environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Relation between tetR and tetA expression in tetracycline resistant Escherichia coli

    DEFF Research Database (Denmark)

    Møller, Thea S. B.; Overgaard, Martin; Nielsen, Søren S.

    2016-01-01

    Background: Tetracyclines are among the most used antibiotics in livestock worldwide. Resistance is widely disseminated in Escherichia coli, where it is generally mediated by tetracycline efflux pumps, such as TetA. Expression of tetracycline efflux pumps is tightly controlled by the repressor Tet......R, which has been shown to be tetracycline-responsive at sub-MIC tetracycline concentrations. The objective of this study was to investigate the effects of increasing tetracycline concentrations on the growth of TetA-producing E. coli, and to determine how expression of tetA and tetR related to each other...... in different growth phases in the presence of tetracycline. Results: A tetracycline resistant E. coli strain containing tetA and tetR on the chromosome was constructed and cultured in the presence of increasing concentrations of tetracycline. Expression of tetR and tetA was measured at four time points...

  14. High Prevalence of Plasmid-Mediated Quinolone Resistance and IncQ Plasmids Carrying qnrS2 Gene in Bacteria from Rivers near Hospitals and Aquaculture in China.

    Directory of Open Access Journals (Sweden)

    Yanping Wen

    Full Text Available Effluents from hospital and aquaculture are considered important sources of quinolone resistance. However, little information is available on the impact of this effluent on nearby rivers. In this study, 188 ciprofloxacin-resistant bacterial isolates obtained from rivers near hospitals and aquaculture were screened for plasmid-mediated quinolone resistance (PMQR genes. Species identification, antibiotic susceptibility testing, and PMQR gene transferability assessment were conducted for PMQR-positive bacteria. Representative qnrS2-encoding plasmids were subsequently sequenced using a primer-walking approach. In total, 44 isolates (23.4% were positive for qnr genes (16 qnrB2, 3 qnrS1, and 25 qnrS2 and 32 isolates (17.0% were positive for aac(6'-Ib-cr. Other PMQR genes were not detected. The qnrB2 and aac(6'-Ib-cr genes had a higher prevalence in aquaculture samples than in hospital samples, and were significantly associated with Enterobacteriaceae (p < 0.05. In contrast, the prevalence of qnrS2 was not site-related, but was significantly associated with Aeromonas spp. (p < 0.05. All PMQR isolates were resistant to three or more classes of antibiotics. Eleven qnrS2-harboring plasmids from Aeromonas spp., including a novel conjugative plasmid pHP18, were selected for sequencing. These plasmids were small in size (6,388-16,197 bp and belonged to the IncQ or IncU plasmid family, with qnrS2 being part of a mobile insertion cassette. Taken together, our findings suggest that aquaculture is a possible source for aac(6'-Ib-cr and qnrB2 dissemination, and demonstrate the ubiquity of qnrS2 in aquatic environments. Finally, Aeromonas spp. served as vectors for qnrS2 with the help of IncQ-type plasmids.

  15. Spread of tetracycline resistance genes at a conventional dairy farm

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, H.; Elhottová, Dana

    2015-01-01

    Roč. 6, may (2015), s. 536 ISSN 1664-302X R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 ; RVO:60077344 Keywords : antibiotic resistance spread * animal manure * cattle intestinal microflora * chlortetracycline * dairy cattle * dairy farm * heavy metals * tetracycline resistance genes Subject RIV: EI - Biotechnology ; Bionics; EE - Microbiology, Virology (BC-A) Impact factor: 4.165, year: 2015

  16. Relation between tetR and tetA expression in tetracycline resistant Escherichia coli

    DEFF Research Database (Denmark)

    Møller, Thea S. B.; Overgaard, Martin; Nielsen, Søren S.

    2016-01-01

    Background: Tetracyclines are among the most used antibiotics in livestock worldwide. Resistance is widely disseminated in Escherichia coli, where it is generally mediated by tetracycline efflux pumps, such as TetA. Expression of tetracycline efflux pumps is tightly controlled by the repressor Tet...

  17. Selfish restriction modification genes: resistance of a resident R/M plasmid to displacement by an incompatible plasmid mediated by host killing.

    Science.gov (United States)

    Naito, Y; Naito, T; Kobayashi, I

    1998-01-01

    Previous work from this laboratory demonstrated that plasmids carrying a type II restriction-modification gene complex are not easily lost from their bacterial host because plasmid-free segregant cells are killed through chromosome cleavage. Here, we have followed the course of events that takes place when an Escherichia coli rec BC sbcA strain carrying a plasmid coding for the PaeR7I restriction-modification (R/M) gene complex is transformed by a plasmid with an identical origin of replication. The number of transformants that appeared was far fewer than with the restriction-minus (r-) control. Most of the transformants were very small. After prolonged incubation, the number and the size of the colonies increased, but this increase never attained the level of the r- control. Most of the transformed colonies retained the drug-resistance of the resident, r+ m+ plasmid. These results indicate that post-segregational host killing occurs when a plasmid bearing an R/M gene complex is displaced by an incompatible plasmid. Such cell killing eliminates the competitor plasmid along with the host and, thus, would allow persistence of the R/M plasmid in the neighboring, clonal host cells in nature. This phenomenon is reminiscent of mammalian apoptosis and other forms of altruistic cell death strategy against infection. This type of resistance to displacement was also studied in a wild type Escherichia coli strain that was normal for homologous recombination (rec+). A number of differences between the recBC sbcA strain and the rec+ strain were observed and these will be discussed.

  18. Antimicrobial susceptibility and tetracycline resistance determinant genotyping of Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Vazquez, Maria E.; Bager, Ragnhild J.

    2011-01-01

    no determinant was identified.This is the first study to determine the antimicrobial susceptibility of Gallibacterium anatis by MIC revealing that multidrug resistance is very common among G. anatis field isolates. tet(B) was by far the most common determinant identified but future work should aim at identifying......The present investigation was undertaken to assess the antimicrobial susceptibility of a collection of 58 Gallibacterium isolates. All strains were tested by the broth dilution method using the veterinary fastidious medium. A total of 46 field strains were tested, whereof 23 were clinical isolates....... Multidrug resistance (resistance towards≥three drugs) was observed for 65% of the field strains and only two strains were susceptible to all compounds. Most prominently, resistance to tetracycline and sulfamethoxazole was observed in 92% and 97% of the field strains, respectively. For comparison...

  19. Effect of tetracycline residues in pig manure slurry on tetracycline-resistant bacteria and resistance gene tet(M) in soil microcosms

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Wulff, Gitte; Vaclavik, Elvira

    2006-01-01

    and oxytetracycline were almost stable through out the experimental period, but the tetracycline concentrations had no effect on prevalence of tetracycline-resistant bacteria. The presented microcosm approach simulated natural farmland conditions well and supported results from previous field studies. (c) 2006...

  20. Plasmid-mediated UV-protection in Streptococcus lactis

    Energy Technology Data Exchange (ETDEWEB)

    Chopin, M.C.; Rouault, A. (Institut National de la Recherche Agronomique, Rennes (France). Lab. de Recherches de Technologie Laitiere); Moillo-Batt, A. (Institut National de la Sante et de la Recherche Medicale (INSERM), Hopital de Pontchaillon, 35 - Rennes (France))

    1985-02-01

    Streptococcus lactis strain IL594 contains 9 plasmids, designated pIL1 to pIL9. On the basis of protoplast-induced curing experiments the authors showed that derivatives containing pIL7 were resistant to UV-irradiation while derivatives lacking pIL7 were sensitive. The pIL7-determined UV-protection was confirmed by co-transfer of the plasmid and of the character into a plasmid-free derivative of S. lactis IL594. Moreover, prophage induction required higher UV-fluence in this derivative carrying pIL7 than in the plasmid-free strain. This is the first report of a plasmid-mediated UV-protection in group N streptococci.

  1. Plasmid-mediated UV-protection in Streptococcus lactis

    International Nuclear Information System (INIS)

    Chopin, M.-C.; Rouault, A.

    1985-01-01

    Streptococcus lactis strain IL594 contains 9 plasmids, designated pIL1 to pIL9. On the basis of protoplast-induced curing experiments the authors showed that derivatives containing pIL7 were resistant to UV-irradiation while derivatives lacking pIL7 were sensitive. The pIL7-determined UV-protection was confirmed by cotransfer of the plasmid and of the character into a plasmid-free derivative of S. lactis IL594. Moreover, prophage induction required higher UV-fluence in this derivative carrying pIL7 than in the plasmid-free strain. This is the first report of a plasmid-mediated UV-protection in group N streptococci. (orig.)

  2. Tetracycline resistance in semi-arid agricultural soils under long-term swine effluent application.

    Science.gov (United States)

    Popova, Inna E; Josue, Rosemarie D R; Deng, Shiping; Hattey, Jeffory A

    2017-05-04

    Annually, millions pounds of antibiotics are released unmetabolized into environment along with animal wastes. Accumulation of antibiotics in soils could potentially induce the persistence of antibiotic resistant bacteria. Antibiotics such as tetracyclines and tetracycline-resistant bacteria have been previously detected in fields fertilized with animal manure. However, little is known about the accumulation of tetracyclines and the development of tetracycline resistance in semi-arid soils. Here we demonstrate that continuous land application with swine effluent, containing trace amounts of chlortetracycline, does not necessarily induce tetracycline resistance in soil bacteria. Based on the testing of more than 3,000 bacteria isolated from the amended soils, we found no significant increase in the occurrence and level of chlortetracycline resistant bacteria in soils after 15 years of continuous swine effluent fertilization. To account for a possible transfer of tetracycline-resistant bacteria originated from the swine effluent to soils, we analyzed two commonly found tetracycline resistant genes, tet(O) and tet(M), in the swine effluent and fertilized soils. Both genes were present in the swine effluent, however, they were not detectable in soils applied with swine effluent. Our data demonstrate that agronomic application of manure from antibiotic treated swine effluent does not necessarily result in the development of antibiotic bacterial resistance in soils. Apparently, concentrations of chlortetracycline present in manure are not significant enough to induce the development of antibiotic bacterial resistance.

  3. Plasmid-mediated mineralization of 4-chlorobiphenyl

    International Nuclear Information System (INIS)

    Shields, M.S.; Hooper, S.W.; Sayler, G.S.

    1985-01-01

    Strains of Alcaligenes and Acinetobacter spp. were isolated from a mixed culture already proven to be proficient at complete mineralization of monohalogenated biphenyls. These strains were shown to harbor a 35 x 10(6)-dalton plasmid mediating a complete pathway for 4-chlorobiphenyl (4CB) oxidation. Subsequent plasmid curing of these bacteria resulted in the abolishment of the 4CB mineralization phenotype and loss of even early 4CB metabolism by Acinetobacter spp. Reestablishment of the Alcaligenes plasmid, denoted pSS50, in the cured Acinetobacter spp. via filter surface mating resulted in the restoration of 4CB mineralization abilities. 4CB mineralization, however, proved to be an unstable characteristic in some subcultured strains. Such loss was not found to coincide with any detectable alteration in plasmid size. Cultures capable of complete mineralization, as well as those limited to partial metabolism of 4CB, produced 4-chlorobenzoate as a metabolite. Demonstration of mineralization of a purified 14 C-labeled chlorobenzoate showed it to be a true intermediate in 4CB mineralization. Unlike the mineralization capability, the ability to produce a metabolite has proven to be stable on subculture. These results indicate the occurrence of a novel plasmid, or evolved catabolic plasmid, that mediates the complete mineralization of 4CB

  4. Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt.

    Science.gov (United States)

    El-Razik, K A Abd; Arafa, A A; Hedia, R H; Ibrahim, E S

    2017-06-01

    This study was devoted to elucidate the tetracycline resistance of coagulase-negative staphylococci (CNS) derived from normal and subclinical mastitic (SCM) buffaloes' milk in Egypt. A total of 81 milk samples from 46 normal buffalo milk samples and 35 SCM buffalo milk samples at private dairy farms of Egypt were used in this study. CNS were identified using phenotypic and molecular methods (polymerase chain reaction [PCR]). CNS isolates were tested for tetracycline resistance using routine methods and multiplex PCR targeting tetracycline ( tet ) resistance genes followed by sequencing of positive PCR products and phylogenetic analysis. Isolation and identification of 28 (34.5%) CNS from normal and SCM buffaloes' milk, namely, Staphylococcus intermedius (39.2%), Staphylococcus xylosus (25.0%), Staphylococcus epidermidis (10.7%), Staphylococcus hominis (10.7%), and 3.5% to each of Staphylococcus sciuri , Staphylococcus hyicus , Staphylococcus lugdunensis , and Staphylococcus simulans . Using nested PCR, all the 28 CNS isolates revealed positive for 16srRNA gene specific for genus staphylococci and negative for thermonuclease ( nuc ) gene specific for Staphylococcus aureus species. The presence of tetracycline resistance-encoding genes ( tet K, tet L, tet M, and tet O) was detected by multiplex PCR. All isolates were negative for tet L, M, and O genes while 14 (50%) CNS isolates were positive for tet K gene, namely, S. lugdunensis (100%), S. hominis (100%), S. epidermidis (66.6%), S. intermedius (45.4%), and S. xylosus (42.8%). Nucleotide sequencing of tet K gene followed by phylogenetic analysis showed the high homology between our CNS isolates genes of tetracycline resistance with S. aureus isolates including Egyptian ones. This proves the transfer of the tetracycline resistance encoding genes between coagulase-negative and coagulase positive Staphylococcus spp. CNS isolates have distinguishingly high resistance to tetracycline. Abundant tetracycline usage for

  5. Spread of tetracycline resistance genes at a conventional dairy farm

    Directory of Open Access Journals (Sweden)

    Martina eKyselkova

    2015-05-01

    Full Text Available The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of smaller farms remains to be evaluated. Here we monitor the spread of tetracycline resistance (TC-r genes at a middle-size conventional dairy farm, where chlortetracycline (CTC, as intrauterine suppository is prophylactically used after each calving. Our study has shown that animals at the farm acquired the TC-r genes in their early age (1-2 weeks, likely due to colonization with TC-resistant bacteria from their mothers and/or the farm environment. The relative abundance of the TC-r genes tet(W, tet(Q and tet(M in fresh excrements of calves was about 1-2 orders of magnitude higher compared to heifers and dairy cows, possibly due to the presence of antibiotic residues in milk fed to calves. The occurrence and abundance of TC-r genes in fresh excrements of heifers and adult cows remained unaffected by intrauterine CTC applications, with tet(O, tet(Q and tet(W representing a ‘core TC-resistome’ of the farm, and tet(A, tet(M, tet(Y and tet(X occurring occasionally. The genes tet(A, tet(M, tet(Y and tet(X were shown to be respectively harbored by Shigella, Lactobacillus and Clostridium, Acinetobacter, and Wautersiella. Soil in the farm proximity, as well as field soil to which manure from the farm was applied, was contaminated with TC-r genes occurring in the farm, and some of the TC-r genes persisted in the field over 3 months following the manure application. Concluding, our study shows that antibiotic resistance genes may be a stable part of the intestinal metagenome of cattle even if antibiotics are not used for growth stimulation, and that smaller dairy farms may also contribute to environmental pollution with antibiotic resistance genes.

  6. Quantifying tetracycline resistance genes in swine waste anaerobic digester over a period of 100 days

    Science.gov (United States)

    Unregulated use of growth promoting antibiotics like Tetracyclines in agricultural feeds is becoming an increasing problem in antibiotic resistance. Undigested antibiotics leads to significant concentrations in livestock waste. These concentrations provide continuous selection pressure for the devel...

  7. Spread of Staphylococcus aureus resistant to penicillin and tetracycline within and between dairy herds

    DEFF Research Database (Denmark)

    Waage, S.; Bjorland, J.; Caugant, D. A.

    2002-01-01

    One hundred and seven bovine isolates of penicillin and tetracycline resistant Staphylococcus aureus, recovered from 25 different dairy herds in various parts of Norway, were characterized using antimicrobial susceptibility testing, multilocus enzyme electrophoresis, ribotyping, plasmid analysis ...

  8. Tetracycline resistance and presence of tetracycline resistance determinants .i.tet./i.(V) and .i.tap./i. in rapidly growing mycobacteria from agricultural soils and clinical isolates

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Chroňáková, Alica; Volná, Lucie; Němec, Jan; Ulmann, V.; Scharfen, J.; Elhottová, Dana

    2012-01-01

    Roč. 27, č. 4 (2012), s. 413-422 ISSN 1342-6311 R&D Projects: GA ČR GAP504/10/2077; GA MŠk LC06066 Institutional support: RVO:60077344 Keywords : efflux pump * rapidly growing Mycobacterium * tetracycline resistance * tap * tet (V) Subject RIV: EH - Ecology, Behaviour Impact factor: 2.444, year: 2012

  9. Organic acids enhance bioavailability of tetracycline in water to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-11-15

    Tetracyclines are a large class of antimicrobials used most extensively in livestock feeding operations. A large portion of tetracyclines administered to livestock is excreted in manure and urine which is collected in waste lagoons. Subsequent land application of these wastes introduces tetracyclines into the soil environment, where they could exert selective pressure for the development of antibiotic resistance genes in bacteria. Tetracyclines form metal-complexes in natural waters, which could reduce their bioavailability for bacterial uptake. We hypothesized that many naturally-occurring organic acids could effectively compete with tetracyclines as ligands for metal cations, hence altering the bioavailability of tetracyclines to bacteria in a manner that could enhance the selective pressure. In this study, we investigated the influence of acetic acid, succinic acid, malonic acid, oxalic acid and citric acid on tetracycline uptake from water by Escherichia coli bioreporter construct containing a tetracycline resistance gene which induces the emission of green fluorescence when activated. The presence of the added organic acid ligands altered tetracycline speciation in a manner that enhanced tetracycline uptake by E. coli. Increased bacterial uptake of tetracycline and concomitant enhanced antibiotic resistance response were quantified, and shown to be positively related to the degree of organic acid ligand complexation of metal cations in the order of citric acid > oxalic acid > malonic acid > succinic acid > acetic acid. The magnitude of the bioresponse increased with increasing aqueous organic acid concentration. Apparent positive relation between intracellular tetracycline concentration and zwitterionic tetracycline species in aqueous solution indicates that (net) neutral tetracycline is the species which most readily enters E. coli cells. Understanding how naturally-occurring organic acid ligands affect tetracycline speciation in solution, and how speciation

  10. Insight into synergetic mechanisms of tetracycline and the selective serotonin reuptake inhibitor, sertraline, in a tetracycline-resistant strain of Escherichia coli

    DEFF Research Database (Denmark)

    Li, Lili; Kromann, Sofie; Olsen, John Elmerdahl

    2017-01-01

    further decreases pH, resulting in cell death. This study shows that sertraline interacts with tetracycline in a synergistic and AcrAB-TolC pump-independent manner. The combinational treatment was further shown to induce many changes in the global transcriptome, including altered tetA and tetR expression......Sertraline, an antidepressive drug, has been reported to inhibit general bacterial efflux pumps. In the present study, we report for the first time a synergistic effect of sertraline and tetracycline in a TetA-encoded tetracycline-resistant strain of Escherichia coli. Synergy between sertraline...... '1). RNA data suggest changes in respiration that is likely to decrease intracellular pH and thereby the proton-motive force, which provides the energy for the tetracycline efflux pump. Furthermore, sertraline and tetracycline may induce a change from oxidation to fermentation in the E.coli, which...

  11. Detection and Characterizations of Genes Resistant to Tetracycline and Sulfa among the Bacteria in Mariculture Water

    Science.gov (United States)

    Qu, L.; Li, Y.; Zhu, P.

    2013-12-01

    One hundred and thirty-five bacteria from maricultural environments were tested for sensitivity to tetracycline and sulfa. Result show that 72% of the bacteria were sulfa-resistant, 36% of the bacteria were tetracycline-resistant, and 16.5% of bacteria showed resistance to both tetracyclines and sulfa ,indicating that the proportion of sulfa and tetracycline resistance bacteria isvery large in the maricultural environments. PCR methods were used to detect if these resistant bacteria carry tetracycline and sulfa resistance genes. Out of the 33 tetracycline-resistant bacteria screened, 3 were positive for tetA, 6 were positive for tetB and no isolate wasboth positive for tetA and tetB. Of the 97 sulfa-resistant bacteria screened, 9 were positive for sul2, 6 were positive for sul1, 1 isolate was positive for bothsul1 and sul2. The minimum inhibitory concentration (MIC) of tetracycline for tetA-carrying isolates were higher than those tetB-carrying isolates.while The MIC of sulfa for sul2-carrying isolates were higher than those sul1-carrying isolates. Indicating that tetA and sul2 gene may play ubknown roles in resisting tetracycline and sulfa than tetB and sul1 genes. The results showed the 4 kinds of genes (tetA,tetB,sul1,sul2) has no host specificity. All these 16S sequence are from the isolates which are positive for the above genes, it indicated the above antibiotic resistance genes are widespread in the environment regardless of the host. While the DNA sequence of these four genes showed tetA, sul1, sul2 genes are conservative in different bacteria , etB gene conserved poorly. The research aim is to get a preliminary understanding of resistance mechanism related to the resistant bacteria and the resistance genes in marine aquaculture environment through the analysis of resistant genes, providing research base for the prevention and treatment of drug-resistant bacteria so as to reduce the threat to the ecological environment, aquaculture and human health.

  12. Tetracycline resistance phenotypes and genotypes of coagulase-negative staphylococcal isolates from bubaline mastitis in Egypt

    Directory of Open Access Journals (Sweden)

    K. A. Abd El-Razik

    2017-06-01

    Full Text Available Aim: This study was devoted to elucidate the tetracycline resistance of coagulase-negative staphylococci (CNS derived from normal and subclinical mastitic (SCM buffaloes' milk in Egypt. Materials and Methods: A total of 81 milk samples from 46 normal buffalo milk samples and 35 SCM buffalo milk samples at private dairy farms of Egypt were used in this study. CNS were identified using phenotypic and molecular methods (polymerase chain reaction [PCR]. CNS isolates were tested for tetracycline resistance using routine methods and multiplex PCR targeting tetracycline (tet resistance genes followed by sequencing of positive PCR products and phylogenetic analysis. Results: Isolation and identification of 28 (34.5% CNS from normal and SCM buffaloes' milk, namely, Staphylococcus intermedius (39.2%, Staphylococcus xylosus (25.0%, Staphylococcus epidermidis (10.7%, Staphylococcus hominis (10.7%, and 3.5% to each of Staphylococcus sciuri, Staphylococcus hyicus, Staphylococcus lugdunensis, and Staphylococcus simulans. Using nested PCR, all the 28 CNS isolates revealed positive for 16srRNA gene specific for genus staphylococci and negative for thermonuclease (nuc gene specific for Staphylococcus aureus species. The presence of tetracycline resistance-encoding genes (tetK, tetL, tetM, and tetO was detected by multiplex PCR. All isolates were negative for tetL, M, and O genes while 14 (50% CNS isolates were positive for tetK gene, namely, S. lugdunensis (100%, S. hominis (100%, S. epidermidis (66.6%, S. intermedius (45.4%, and S. xylosus (42.8%. Nucleotide sequencing of tetK gene followed by phylogenetic analysis showed the high homology between our CNS isolates genes of tetracycline resistance with S. aureus isolates including Egyptian ones. This proves the transfer of the tetracycline resistance encoding genes between coagulase-negative and coagulase-positive Staphylococcus spp. Conclusion: CNS isolates have distinguishingly high resistance to tetracycline

  13. Characterization of transferable tetracycline resistance genes in Enterococcus faecalis isolated from raw food

    DEFF Research Database (Denmark)

    Wilcks, Andrea; Andersen, Sigrid Rita; Licht, Tine Rask

    2005-01-01

    The prevalence of tetracycline resistance, and of specific genetic determinants for this resistance was investigated in 1003 strains of Enterococcus faecalis isolated from various raw food products originating from five categories including chicken meat, other poultry meat, beef, pork, and 'other...

  14. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    International Nuclear Information System (INIS)

    Huang, Manhong; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-01-01

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge

  15. Changes of bacterial diversity and tetracycline resistance in sludge from AAO systems upon exposure to tetracycline pressure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Manhong, E-mail: egghmh@163.com; Qi, Fangfang; Wang, Jue; Xu, Qi; Lin, Li

    2015-11-15

    Highlights: • High-throughput sequencing was used to compare sludge bacteria with and without TC. • Bacterial diversity increased with TC addition despite of various oxygen conditions. • Total TRGs proliferated with TC addition in three kinds of sludge. • The concentration of efflux pump genes was the highest in the three groups of TRGs. - Abstract: Two lab-scale anaerobic-anoxic-oxic (AAO) systems were used to investigate the changes in tetracycline (TC) resistance and bacterial diversity upon exposure to TC pressure. High-throughput sequencing was used to detect diversity changes in microorganisms at the level of class in sludge from different bioreactors with and without TC. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) was used to detect the abundances of eight tetracycline resistance genes (TRGs), tetA, tetB, tetC, tetE, tetM, tetO, tetS and tetX. The results showed that the diversities of the microbial communities of anoxic, anaerobic and aerobic sludge all increased with the addition of TC. TC substantially changed the structure of the microbial community regardless of oxygen conditions. Bacteroidetes and Proteobacteria were the dominant species in the three kinds of sludge and were substantially enriched with TC pressure. In sludge with TC added, almost all target TRGs proliferated more than those in sludge without TC except tetX, which decreased in anaerobic sludge with TC addition. The concentration of efflux pump genes, tet(A–C, E), was the highest among the three groups of TRGs in the different kinds of sludge.

  16. Cow excrements enhance the occurrence of tetracycline resistance genes in soil regardless of their oxytetracycline content

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Chroňáková, Alica; Vrchotová, Naděžda; Bradley, R.; Schmitt, H.; Elhottová, Dana

    2013-01-01

    Roč. 93, č. 10 (2013), s. 2413-2418 ISSN 0045-6535 R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) ED1.1.00/02.0073 Grant - others:OECD(FR) JA00054767 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : cattle excrement * environmental risk assessment * manured soil * oxytetracycline * tetracycline resistance * tetracycline resistance gene Subject RIV: EE - Microbiology, Virology Impact factor: 3.499, year: 2013

  17. Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Dagmar Chudobova

    2014-03-01

    Full Text Available There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health.

  18. Effect of Ampicillin, Streptomycin, Penicillin and Tetracycline on Metal Resistant and Non-Resistant Staphylococcus aureus

    Science.gov (United States)

    Chudobova, Dagmar; Dostalova, Simona; Blazkova, Iva; Michalek, Petr; Ruttkay-Nedecky, Branislav; Sklenar, Matej; Nejdl, Lukas; Kudr, Jiri; Gumulec, Jaromir; Tmejova, Katerina; Konecna, Marie; Vaculovicova, Marketa; Hynek, David; Masarik, Michal; Kynicky, Jindrich; Kizek, Rene; Adam, Vojtech

    2014-01-01

    There is an arising and concerning issue in the field of bacterial resistance, which is confirmed by the number of deaths associated with drug-resistant bacterial infections. The aim of this study was to compare the effects of antibiotics on Staphylococcus aureus non-resistant strain and strains resistant to cadmium or lead ions. Metal resistant strains were created by the gradual addition of 2 mM solution of metal ions (cadmium or lead) to the S. aureus culture. An increasing antimicrobial effect of ampicillin, streptomycin, penicillin and tetracycline (0, 10, 25, 50, 75, 150, 225 and 300 µM) on the resistant strains was observed using a method of growth curves. A significant growth inhibition (compared to control) of cadmium resistant cells was observed in the presence of all the four different antibiotics. On the other hand, the addition of streptomycin and ampicillin did not inhibit the growth of lead resistant strain. Other antibiotics were still toxic to the bacterial cells. Significant differences in the morphology of cell walls were indicated by changes in the cell shape. Our data show that the presence of metal ions in the urban environment may contribute to the development of bacterial strain resistance to other substances including antibiotics, which would have an impact on public health. PMID:24651395

  19. The tetracycline resistance determinant Tet 39 and the sulphonamide resistance gene sulII are common among resistant Acinetobacter spp. isolated from integrated fish farms in Thailand

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Petersen, Andreas

    2007-01-01

    Objectives: To determine the genetic basis for tetracycline and sulphonamide resistance and the prevalence of class I and II integrons in oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Methods: A total of 222 isolates were screened for tetracycline resistance...... and Southern blots with sulII and tet(39) probes were performed on selected isolates. Results: The recently identified tetracycline resistance gene tet(39) was demonstrated in 75% (166/222) of oxytetracycline-resistant Acinetobacter spp. from integrated fish farms in Thailand. Isolates that were also...

  20. Role of tetracycline speciation in the bioavailability to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-05-06

    Tetracycline contains ionizable functional groups that manifest several species with charges at different locales and differing net charge; the fractional distribution of each species depends on pH-pKa relationship in the aqueous phase. In nature, these species interact with naturally abundant cations (e.g., Ca(2+) and Mg(2+)) to form metal-tetracycline complexes in water. In this study, we used Escherichia coli MC4100/pTGM whole-cell bioreporter to investigate tetracycline uptake from solution under varying conditions of pH, salt composition and concentration by quantifying the corresponding expression of antibiotic resistance gene. The expression of antibiotic resistance gene in the E. coli bioreporter responded linearly to intracellular tetracycline concentration. Less tetracycline entered E. coli cells at solution pH of 8.0 than at pH 6.0 or 7.0 indicating reduced bioavailability of the antibiotic at higher pH. Both Mg(2+) and Ca(2+) in solution formed metal-tetracycline complexes which reduced uptake of tetracycline by E. coli hence diminishing the bioresponse. Among the various tetracycline species present in solution, including both metal-complexed and free (noncomplexed) species, zwitterionic tetracycline was identified as the predominant species that most readily passed through the cell membrane eliciting activation of the antibiotic resistance gene in E. coli. The results indicate that the same total concentration of tetracycline in ambient solution can evoke very different expression of antibiotic resistance gene in the exposed bacteria due to differential antibiotic uptake. Accordingly, geochemical factors such as pH and metal cations can modulate the selective pressure exerted by tetracycline for development and enrichment of antibiotic resistant bacteria. We suggest that tetracycline speciation analysis should be incorporated into the risk assessment framework for evaluating environmental exposure and the corresponding development of antibiotic

  1. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    International Nuclear Information System (INIS)

    Tao Ran; Ying Guangguo; Su Haochang; Zhou Hongwei; Sidhu, Jatinder P.S.

    2010-01-01

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  2. Detection of antibiotic resistance and tetracycline resistance genes in Enterobacteriaceae isolated from the Pearl rivers in South China

    Energy Technology Data Exchange (ETDEWEB)

    Tao Ran [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Ying Guangguo, E-mail: guangguo.ying@gmail.co [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Su Haochang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Tianhe District, Guangzhou 510640 (China); Zhou Hongwei [Department of Environmental Health, School of Public Health and Tropical Medicine, Southern Medical University, 1838 North Guangzhou Street, Baiyun District, Guangzhou 510515 (China); Sidhu, Jatinder P.S. [CSIRO Land and Water, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067 (Australia)

    2010-06-15

    This study investigated antibiotic resistance profiles and tetracycline resistance genes in Enterobacteriaceae family isolates from the Pearl rivers. The Enterobacteriaceae isolates were tested for susceptibility to seven antibiotics ampicillin, chloramphenicol, ciprofloxacin, levofloxacin, sulphamethoxazole/trimethoprim, tetracycline and trimethoprim. In Liuxi reservoir, with an exception to ampicillin resistant strains (11%) no other antibiotic resistance bacterial strains were detected. However, multiple drug resistance in bacterial isolates from the other sites of Pearl rivers was observed which is possibly due to sewage discharge and input from other anthropogenic sources along the rivers. Four tetracycline resistance genes tet A, tet B, tet C and tet D were detected in the isolates from the rivers. The genes tet A and tet B were widely detected with the detection frequencies of 43% and 40% respectively. Ciprofloxacin and levofloxacin resistant enteric bacteria were also isolated from the pig and duck manures which suggest a wider distribution of human specific drugs in the environment. This investigation provided a baseline data on antibiotic resistance profiles and tetracycline resistance genes in the Pearl rivers delta. - High rates of antibiotic resistance in Enterobacteriaceae from river water are attributed to wastewater contamination.

  3. Prevalence and molecular characterization of plasmid- mediated ...

    African Journals Online (AJOL)

    Pseudomonas aeruginisa, Acinetobacter baumannii and. Klebsiella pneumomiae in Brooklyn, NY. J Antimicrob. Chemother 2007; 60: 78-82. 12. Busato C, Gabardo J, Leão M. The evolution of the resistance of Staphylococcus aureus found on healthcare workers correlated with local consumption of antibiotics. Braz J Infect ...

  4. Resistance to the tetracyclines and macrolide-lincosamide-streptogramin group of antibiotics and its genetic linkage – a review

    Directory of Open Access Journals (Sweden)

    Durdica Marosevic

    2017-06-01

    Full Text Available An excessive use of antimicrobial agents poses a risk for the selection of resistant bacteria. Of particular interest are antibiotics that have large consumption rates in both veterinary and human medicine, such as the tetracyclines and macrolide-lincosamide-streptogramin (MLS group of antibiotics. A high load of these agents increases the risk of transmission of resistant bacteria and/or resistance determinants to humans, leading to a subsequent therapeutic failure. An increasing incidence of bacteria resistant to both tetracyclines and MLS antibiotics has been recently observed. This review summarizes the current knowledge on different tetracycline and MLS resistance genes that can be linked together on transposable elements.

  5. The gut as reservoir of antibiotic resistance: microbial diversity of tetracycline resistance in mother and infant.

    Directory of Open Access Journals (Sweden)

    Lisbeth E de Vries

    Full Text Available The microbiota in the human gastrointestinal tract (GIT is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a case study using a metagenomic approach to determine the diversity of microorganisms conferring tetracycline resistance (Tc(r in the guts of a healthy mother-infant pair one month after childbirth, and to investigate the potential for horizontal transfer and maternal transmission of Tc(r genes. Fecal fosmid libraries were functionally screened for Tc(r, and further PCR-screened for specific Tc(r genes. Tc(r fosmid inserts were sequenced at both ends to establish bacterial diversity. Mother and infant libraries contained Tc(r, although encoded by different genes and organisms. Tc(r organisms in the mother consisted mainly of Firmicutes and Bacteroidetes, and the main gene detected was tet(O, although tet(W and tet(X were also found. Identical Tc(r gene sequences were present in different bacterial families and even phyla, which may indicate horizontal transfer within the maternal GIT. In the infant library, Tc(r was present exclusively in streptococci carrying tet(M, tet(L and erm(T within a novel composite transposon, Tn6079. This transposon belongs to a family of broad host range conjugative elements, implying a potential for the joint spread of tetracycline and erythromycin resistance within the infant's gut. In addition, although not found in the infant metagenomic library, tet(O and tet(W could be detected in the uncloned DNA purified from the infant fecal sample. This is the first study to reveal the diversity of Tc(r bacteria in the human gut, to detect a likely transmission of antibiotic resistance from mother to infant GITs and to indicate the possible occurrence of gene transfers among distantly related bacteria coinhabiting the GIT of the same

  6. Mini-Mu insertions in the tetracycline resistance determinant from Proteus mirabilis

    Directory of Open Access Journals (Sweden)

    Magalhães V.D.

    1997-01-01

    Full Text Available The inducible tetracycline resistance determinant isolated from Proteus mirabilis cloned into the plasmid pACYC177 was mutagenized by insertion of a mini-Mu-lac phage in order to define the regions in the cloned sequences encoding the structural and regulatory proteins. Three different types of mutants were obtained: one lost the resistance phenotype and became Lac+; another expressed the resistance at lower levels and constitutively; the third was still dependent on induction but showed a lower minimal inhibitory concentration. The mutant phenotypes and the locations of the insertions indicate that the determinant is composed of a repressor gene and a structural gene which are not transcribed divergently as are other known tetracycline determinants isolated from Gram-negative bacteria

  7. Spread of tetracycline resistance genes at a conventional dairy farm

    NARCIS (Netherlands)

    Kyselková, Martina; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, Heike; Elhottová, Dana

    2015-01-01

    The use of antibiotics in animal husbandry contributes to the worldwide problem of increasing antibiotic resistance in animal and human pathogens. Intensive animal production is considered an important source of antibiotic resistance genes released to the environment, while the contribution of

  8. Widespread distribution of a tet W determinant among tetracycline-resistant isolates of the animal pathogen Arcanobacterium pyogenes.

    Science.gov (United States)

    Billington, Stephen J; Songer, J Glenn; Jost, B Helen

    2002-05-01

    Tetracycline resistance is common among isolates of the animal commensal and opportunistic pathogen Arcanobacterium pyogenes. The tetracycline resistance determinant cloned from two bovine isolates of A. pyogenes was highly similar at the DNA level (92% identity) to the tet(W) gene, encoding a ribosomal protection tetracycline resistance protein, from the rumen bacterium Butyrivibrio fibrisolvens. The tet(W) gene was found in all 20 tetracycline-resistant isolates tested, indicating that it is a widely distributed determinant of tetracycline resistance in this organism. In 25% of tetracycline-resistant isolates, the tet(W) gene was associated with a mob gene, encoding a functional mobilization protein, and an origin of transfer, suggesting that the determinant may be transferable to other bacteria. In fact, low-frequency transfer of tet(W) was detected from mob+ A. pyogenes isolates to a tetracycline-sensitive A. pyogenes recipient. The mobile nature of this determinant and the presence of A. pyogenes in the gastrointestinal tract of cattle and pigs suggest that A. pyogenes may have inherited this determinant within the gastrointestinal tracts of these animals.

  9. Distribution of tetracycline resistance genes in anaerobic treatment of waste sludge: The role of pH in regulating tetracycline resistant bacteria and horizontal gene transfer.

    Science.gov (United States)

    Huang, Haining; Chen, Yinguang; Zheng, Xiong; Su, Yinglong; Wan, Rui; Yang, Shouye

    2016-10-01

    Although pH value has been widely regarded as an important factor that affects resource recovery of waste sludge, the potential influence of diverse pHs on the distribution of tetracycline resistance genes (TRGs) during sludge anaerobic treatment is largely unknown. Here we reported that in the range of pH 4-10, 0.58-1.18 log unit increase of target TRGs was observed at pH 4, compared with that at pH 7, while 0.70-1.31 log unit further removal were obtained at pH 10. Mechanism study revealed that varied pHs not only altered the community structures of tetracycline resistant bacteria (TRB), but also changed their relative abundances, benefitting the propagation (acidic pHs) or attenuation (alkaline pHs) of TRB. Further investigation indicated that the amount and gene-possessing abilities of key genetic vectors for horizontal TRGs transfer were greatly promoted at acidic pHs but restricted under alkaline conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Characterization of resistance to tetracyclines and aminoglycosides of sheep mastitis pathogens: study of the effect of gene content on resistance.

    Science.gov (United States)

    Lollai, S A; Ziccheddu, M; Duprè, I; Piras, D

    2016-10-01

    Mastitis causes economic losses and antimicrobials are frequently used for mastitis treatment. Antimicrobial resistance surveys are still rare in the ovine field and characterization of strains is important in order to acquire information about resistance and for optimization of therapy. Bacterial pathogens recovered in milk samples from mastitis-affected ewes were characterized for resistance to tetracyclines and aminoglycosides, members of which are frequently used antimicrobials in small ruminants. A total of 185 strains of staphylococci, streptococci, and enterococci, common mastitis pathogens, were tested for minimal inhibitory concentration (MIC) to tetracycline, doxycycline, minocycline, gentamicin, kanamycin, streptomycin, and for resistance genes by PCR. Effects of different tet genes arrangements on MICs were also investigated. Staphylococci expressed the lowest MIC for tetracycline and tet(K) was the most common gene recovered; tet(M) and tet(O) were also found. Gene content was shown to influence the tetracycline MIC values. Enterococci and streptococci showed higher MICs to tetracyclines and nonsusceptible strains always harboured at least one ribosomal protection gene (MIC above 8 μg ml(-1) ). Streptococci often harboured two or more tet determinants. As regards the resistance to aminoglycosides, staphylococci showed the lowest gentamicin and kanamycin median MIC along with streptomycin high level resistant (HLR) strains (MIC >1024 μg ml(-1) ) all harbouring str gene. The resistance determinant aac(6')-Ie-aph(2″)-Ia was present in few strains. Streptococci were basically nonsusceptible to aminoglycosides but neither HLR isolates nor resistance genes were detected. Enterococci revealed the highest MICs for gentamicin; two str harbouring isolates were shown to be HLR to streptomycin. Evidence was obtained for the circulation of antimicrobial-resistant strains and genes in sheep dairy farming. Tetracycline MIC of 64 μg ml(-1) and high

  11. Tetracycline resistance and TetM in oral anaerobic bacteria and Neisseria perflava-N. sicca.

    OpenAIRE

    Roberts, M C; Moncla, B J

    1988-01-01

    Tetracycline-resistant organisms isolated from six patients with periodontal disease included Bacteroides spp., Eubacterium spp., Fusobacterium nucleatum, Neisseria perflava-N. sicca, Peptostreptococcus anaerobius, Veillonella parvula, and facultative streptococci. All but the Bacteroides spp. and Eubacterium spp. hybridized with the TetM determinant. An additional 417 bacterial strains were screened, and 4% of both the oral streptococci and the Fusobacterium spp. hybridized with the TetM probe.

  12. Molecular Identification and Quantification of Tetracycline and Erythromycin Resistance Genes in Spanish and Italian Retail Cheeses

    Directory of Open Access Journals (Sweden)

    Ana Belén Flórez

    2014-01-01

    Full Text Available Large antibiotic resistance gene pools in the microbiota of foods may ultimately pose a risk for human health. This study reports the identification and quantification of tetracycline- and erythromycin-resistant populations, resistance genes, and gene diversity in traditional Spanish and Italian cheeses, via culturing, conventional PCR, real-time quantitative PCR (qPCR, and denaturing gradient gel electrophoresis (DGGE. The numbers of resistant bacteria varied widely among the antibiotics and the different cheese varieties; in some cheeses, all the bacterial populations seemed to be resistant. Up to eight antibiotic resistance genes were sought by gene-specific PCR, six with respect to tetracycline, that is, tet(K, tet(L, tet(M, tet(O, tet(S, and tet(W, and two with respect to erythromycin, that is, erm(B and erm(F. The most common resistance genes in the analysed cheeses were tet(S, tet(W, tet(M, and erm(B. The copy numbers of these genes, as quantified by qPCR, ranged widely between cheeses (from 4.94 to 10.18log⁡10/g. DGGE analysis revealed distinct banding profiles and two polymorphic nucleotide positions for tet(W-carrying cheeses, though the similarity of the sequences suggests this tet(W to have a monophyletic origin. Traditional cheeses would therefore appear to act as reservoirs for large numbers of many types of antibiotic resistance determinants.

  13. Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs.

    Science.gov (United States)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders; Herrero-Fresno, Ana; Larsen, Inge; Holm, Anders; Nielsen, Jens Peter; Christiansen, Lasse Engbo; Angen, Øystein; Ahmed, Shahana; Folkesson, Anders; Olsen, John Elmerdahl

    2017-06-15

    This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis -induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested. IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in livestock

  14. Effect of Tetracycline Dose and Treatment Mode on Selection of Resistant Coliform Bacteria in Nursery Pigs

    Science.gov (United States)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders; Herrero-Fresno, Ana; Larsen, Inge; Holm, Anders; Nielsen, Jens Peter; Christiansen, Lasse Engbo; Angen, Øystein; Ahmed, Shahana

    2017-01-01

    ABSTRACT This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig herds were treated with oxytetracycline for Lawsonia intracellularis-induced diarrhea. Each group was randomly allocated to one of five treatment groups: oral flock treatment with a (i) high (20 mg/kg of body weight), (ii) medium (10 mg/kg), or (iii) low (5 mg/kg) dose, (iv) oral pen-wise (small-group) treatment (10 mg/kg), and (v) individual intramuscular injection treatment (10 mg/kg). All groups were treated once a day for 5 days. In all groups, treatment caused a rise in the numbers and proportions of tetracycline-resistant coliform bacteria right after treatment, followed by a significant drop by the time that the pigs left the nursery unit. The counts and proportions of tetracycline-resistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated with tiamulin did not show significant changes in the numbers or proportions of tetracycline-resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant strains but not to selection for cefotaxime-resistant strains. In conclusion, the difference in the dose of oxytetracycline and the way in which the drug was applied did not cause significantly different levels of selection of tetracycline-resistant coliform bacteria under the conditions tested. IMPORTANCE Antimicrobial resistance is a global threat to human health. Treatment of livestock with antimicrobials has a direct impact on this problem, and there is a need to improve the ways that we use antimicrobials in

  15. Tetracycline and Azithromycin Resistance Investigation on Shigella spp. Isolated from the Stool of Children with Diarrhea in Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Shadi Shahsavan

    2016-10-01

    Full Text Available Background & objectives: Shigella spp. are gram negative bacteria that can cause shigellosis in human. It is important in young children as well as elderly and immunocompromised people. Threatening complications can occur in severe cases with multidrug resistance species. It has been observed that Shigella spp. have become resistant to antibiotics like other bacteria. Investigation of resistance to azithromycin, tetracycline and pattern of resistance are the objectives of this study. Methods: Fifty isolates of Shigella spp. which have been collected from three hospitals in Tehran were studied. Isolates identified and confirmed as Shigella spp. by biochemical, serological and molecular methods (ipaH, wbgz, rfc genes. Antimicrobial susceptibility test was performed for ampicillin, azithromycin, ciprofloxacin, doxycycline, levofloxacin, minocycline, nalidixic acid, norfloxacin, streptomycin, trimethoprim-sulfamethoxazole and tetracycline by disc agar diffusion method. Minimal inhibition concentrations were performed for azithromycin and tetracycline. Results: From a total of 50 Shigella spp. isolates, 16% of them were Shigella flexneri and 84% Shigella sonnei. The majority of isolates were multidrug resistant. The most resistance was seen to doxycycline, streptomycin, trimethoprim-sulfamethoxazole and tetracycline. Resistance to azithromycin was 6%  and all of the isolates were susceptible to norfloxacin and levofloxacin. Nine patterns of resistance were revealed to these isolates. Conclusion: High resistance to tetracycline was observed and resistance to azithromycin as an alternative treatment choice was also considerable.

  16. Distribution of quinolones, sulfonamides, tetracyclines in aquatic environment and antibiotic resistance in Indochina

    Directory of Open Access Journals (Sweden)

    Satoru eSuzuki

    2012-02-01

    Full Text Available Southeast Asia has become the center of rapid industrial development and economic growth. However, this growth has far outpaced investment in public infrastructure, leading to the unregulated release of many pollutants, including wastewater-related contaminants such as antibiotics. Antibiotics are of major concern because they can easily be released into the environment from numerous sources, and can subsequently induce development of antibiotic-resistant bacteria. Recent studies have shown that for some categories of drugs this source-to-environment antibiotic resistance relationship is more complex. This review summarizes current understanding regarding the presence of quinolones, sulfonamides, and tetracyclines in aquatic environments of Indochina and the prevalence of bacteria resistant to them. Several noteworthy findings are discussed: 1 quinolone contamination and the occurrence of quinolone resistance are not correlated; 2 occurrence of the sul sulfonamide resistance gene varies geographically; and 3 microbial diversity might be related to the rate of oxytetracycline resistance.

  17. Tetracycline resistance genes persist in soil amended with cattle feces independently from chlortetracycline selection pressure

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Kotrbová, Lucie; Bhumibhamon, G.; Chroňáková, Alica; Jirout, Jiří; Vrchotová, Naděžda; Schmitt, H.; Elhottová, Dana

    2015-01-01

    Roč. 81, February (2015), s. 259-265 ISSN 0038-0717 R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : antibiotic resistance * cattle feces * chlortetracycline * grassland soil * tetracycline resistance genes * intI1 gene Subject RIV: EE - Microbiology, Virology; CE - Biochemistry (UEK-B) Impact factor: 4.152, year: 2015

  18. Helicobacter pylori resistance rates for levofloxacin, tetracycline and rifabutin among Irish isolates at a reference centre.

    LENUS (Irish Health Repository)

    O'Connor, A

    2013-04-27

    INTRODUCTION: Helicobacter pylori eradication rates using conventional triple therapies are falling, making viable second-line and rescue regimens necessary. Levofloxacin, tetracycline and rifabutin are three efficacious antibiotics for rescue therapy. AIM: We aimed to assess the resistance rates for H. pylori against these antibiotics in an Irish cohort. METHODS: Gastric biopsies were collected from 85 patients infected with H. pylori (mean age 46 years) in the Adelaide and Meath Hospital, Dublin in 2008 and 2009. Susceptibility to antibiotics was tested using the Etest. Clinical information was obtained from endoscopy reports and chart review. RESULTS: 50.6 % of patients were females. Mean age was 47 years. Ten had prior attempts at eradication therapy with amoxicillin-clarithromycin-PPI, two had levofloxacin-based second-line therapy. 11.7 % [95 % CI (6.5-20.3 %)] (N = 10) had strains resistant to levofloxacin. There were no strains resistant to rifabutin or tetracycline. Levofloxacin resistance in the under 45 age group was 2.6 % (1\\/38) compared to 19.1 % (9\\/47) of above 45 age group (p = 0.02). DISCUSSION: The levofloxacin rates illustrated in this study are relatively low by European standards and in line with other studies from the United Kingdom and Germany, with younger patients having very low levels of resistance. Levofloxacin, tetracycline and rifabutin are all valid options for H. pylori eradication in Irish patients but the importance of compliance cannot be underestimated.

  19. Occurrence and Diversity of Tetracycline Resistance Genes in Lagoons and Groundwater Underlying Two Swine Production Facilities

    Science.gov (United States)

    Chee-Sanford, J. C.; Aminov, R.I.; Krapac, I.J.; Garrigues-Jeanjean, N.; Mackie, R.I.

    2001-01-01

    In this study, we used PCR typing methods to assess the presence of tetracycline resistance determinants conferring ribosomal protection in waste lagoons and in groundwater underlying two swine farms. All eight classes of genes encoding this mechanism of resistance [tet(O), tet(Q), tet(W), tet(M), tetB(P), tet(S), tet(T), and otrA] were found in total DNA extracted from water of two lagoons. These determinants were found to be seeping into the underlying groundwater and could be detected as far as 250 m downstream from the lagoons. The identities and origin of these genes in groundwater were confirmed by PCR-denaturing gradient gel electrophoresis and sequence analyses. Tetracycline-resistant bacterial isolates from groundwater harbored the tet(M) gene, which was not predominant in the environmental samples and was identical to tet(M) from the lagoons. The presence of this gene in some typical soil inhabitants suggests that the vector of antibiotic resistance gene dissemination is not limited to strains of gastrointestinal origin carrying the gene but can be mobilized into the indigenous soil microbiota. This study demonstrated that tet genes occur in the environment as a direct result of agriculture and suggested that groundwater may be a potential source of antibiotic resistance in the food chain.

  20. Pharmacokinetic-Pharmacodynamic Model To Evaluate Intramuscular Tetracycline Treatment Protocols To Prevent Antimicrobial Resistance in Pigs

    DEFF Research Database (Denmark)

    Ahmad, Amais; Græsbøll, Kaare; Christiansen, Lasse Engbo

    2015-01-01

    High instances of antimicrobial resistance are linked to both routine and excessive antimicrobial use, but excessive or inappropriate use represents an unnecessary risk. The competitive growth advantages of resistant bacteria may be amplified by the strain dynamics; in particular, the extent...... to which resistant strains outcompete susceptible strains under antimicrobial pressure may depend not only on the antimicrobial treatment strategies but also on the epidemiological parameters, such as the composition of the bacterial strains in a pig. This study evaluated how variation in the dosing...... protocol for intramuscular administration of tetracycline and the composition of bacterial strains in a pig affect the level of resistance in the intestine of a pig. Predictions were generated by a mathematical model of competitive growth of Escherichia coli strains in pigs under specified plasma...

  1. Pharmacokinetic-Pharmacodynamic Model To Evaluate Intramuscular Tetracycline Treatment Protocols To Prevent Antimicrobial Resistance in Pigs

    DEFF Research Database (Denmark)

    Ahmad, Amais; Græsbøll, Kaare; Christiansen, Lasse Engbo

    2015-01-01

    protocol for intramuscular administration of tetracycline and the composition of bacterial strains in a pig affect the level of resistance in the intestine of a pig. Predictions were generated by a mathematical model of competitive growth of Escherichia coli strains in pigs under specified plasma......High instances of antimicrobial resistance are linked to both routine and excessive antimicrobial use, but excessive or inappropriate use represents an unnecessary risk. The competitive growth advantages of resistant bacteria may be amplified by the strain dynamics; in particular, the extent...... to which resistant strains outcompete susceptible strains under antimicrobial pressure may depend not only on the antimicrobial treatment strategies but also on the epidemiological parameters, such as the composition of the bacterial strains in a pig. This study evaluated how variation in the dosing...

  2. Monitoring of drug resistance amplification and attenuation with the use of tetracycline-resistant bacteria during wastewater treatment

    Science.gov (United States)

    Harnisz, Monika; Korzeniewska, Ewa; Niestępski, Sebastian; Osińska, Adriana; Nalepa, Beata

    2017-11-01

    The objective of this study was to monitor changes (amplification or attenuation) in antibiotic resistance during wastewater treatment based on the ecology of tetracycline-resistant bacteria. The untreated and treated wastewater were collected in four seasons. Number of tetracycline-(TETR) and oxytetracycline-resistant (OTCR) bacteria, their qualitative composition, minimum inhibitory concentrations (MICs), sensitivity to other antibiotics, and the presence of tet (A, B, C, D, E) resistance genes were determined. TETR and OTCR counts in untreated wastewater were 100 to 1000 higher than in treated effluent. OTCR bacterial counts were higher than TETR populations in both untreated and treated wastewater. TETR isolates were not dominated by a single bacterial genus or species, whereas Aeromonas hydrophila and Aeromonas sobria were the most common in OTCR isolates. The treatment process attenuated the drug resistance of TETR bacteria and amplified the resistance of OTCR bacteria. In both microbial groups, the frequency of tet(A) gene increased in effluent in comparison with untreated wastewater. Our results also indicate that treated wastewater is a reservoir of multiple drug-resistant bacteria as well as resistance determinants which may pose a health hazard for humans and animals when released to the natural environment.

  3. Emergence of Tetracycline Resistance in Helicobacter pylori: Multiple Mutational Changes in 16S Ribosomal DNA and Other Genetic Loci

    Science.gov (United States)

    Dailidiene, Daiva; Bertoli, M. Teresita; Miciuleviciene, Jolanta; Mukhopadhyay, Asish K.; Dailide, Giedrius; Pascasio, Mario Alberto; Kupcinskas, Limas; Berg, Douglas E.

    2002-01-01

    Tetracycline is useful in combination therapies against the gastric pathogen Helicobacter pylori. We found 6 tetracycline-resistant (Tetr) strains among 159 clinical isolates (from El Salvador, Lithuania, and India) and obtained the following four results: (i) 5 of 6 Tetr isolates contained one or two nucleotide substitutions in one part of the primary tetracycline binding site in 16S rRNA (AGA965-967 [Escherichia coli coordinates] changed to gGA, AGc, guA, or gGc [lowercase letters are used to represent the base changes]), whereas the sixth (isolate Ind75) retained AGA965-967; (ii) PCR products containing mutant 16S ribosomal DNA (rDNA) alleles transformed recipient strains to Tetr phenotypes, but transformants containing alleles with single substitutions (gGA and AGc) were less resistant than their Tetr parents; (iii) each of 10 Tetr mutants of reference strain 26695 (in which mutations were induced with metronidazole, a mutagenic anti-H. pylori agent) contained the normal AGA965-967 sequence; and (iv) transformant derivatives of Ind75 and of one of the Tetr 26695 mutants that had acquired mutant rDNA alleles were resistant to tetracycline at levels higher than those to which either parent strain was resistant. Thus, tetracycline resistance in H. pylori results from an accumulation of changes that may affect tetracycline-ribosome affinity and/or other functions (perhaps porins or efflux pumps). We suggest that the rarity of tetracycline resistance among clinical isolates reflects this need for multiple mutations and perhaps also the deleterious effects of such mutations on fitness. Formally equivalent mutations with small but additive effects are postulated to contribute importantly to traits such as host specificity and virulence and to H. pylori's great genetic diversity. PMID:12435699

  4. The rarely reported tet(31) tetracycline resistance determinant is common in Gallibacterium anatis

    DEFF Research Database (Denmark)

    Bojesen, Anders M.; Bager, Ragnhild J.; Ifrah, Dan

    2011-01-01

    The present investigation was undertaken to identify and characterize the tetracycline resistance determinant in 22 Gallibacterium anatis strains for which no determinant was identified using primers specific for tet(A, B, C, D, E, G, H, K, L, M, O). A recent study found tet(B) to be the most pre...... from very different production systems and localities. In addition, tet(31) was identified in strains isolated over a 30-year period. This is the first report on tet(31) since its original identification in Aeromonas salmonicida....

  5. Rapid startup of thermophilic anaerobic digester to remove tetracycline and sulfonamides resistance genes from sewage sludge.

    Science.gov (United States)

    Xu, Rui; Yang, Zhao-Hui; Wang, Qing-Peng; Bai, Yang; Liu, Jian-Bo; Zheng, Yue; Zhang, Yan-Ru; Xiong, Wei-Ping; Ahmad, Kito; Fan, Chang-Zheng

    2018-01-15

    Spread of antibiotic resistance genes (ARGs) originating from sewage sludge is highlighted as an eminent health threat. This study established a thermophilic anaerobic digester using one-step startup strategy to quickly remove tetracycline and sulfonamides resistance genes from sewage sludge. At least 20days were saved in the startup period from mesophilic to thermophilic condition. Based on the results of 16S rDNA amplicons sequencing and predicted metagenomic method, the successful startup largely relied on the fast colonization of core thermophilic microbial population (e.g. Firmicutes, Proteobacteria, Actinobacteria). Microbial metabolic gene pathways for substrate degradation and methane production was also increased by one-step mode. In addition, real-time quantitative PCR approach revealed that most targeted tetracycline and sulfonamides resistance genes ARGs (sulI, tetA, tetO, tetX) were substantially removed during thermophilic digestion (removal efficiency>80%). Network analysis showed that the elimination of ARGs was attributed to the decline of their horizontal (intI1 item) and vertical (potential hosts) transfer-related elements under high-temperature. This research demonstrated that rapid startup thermophilic anaerobic digestion of wastewater solids would be a suitable technology for reducing quantities of various ARGs. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

    African Journals Online (AJOL)

    The most frequent β-lactamase type was cefotaximase (CTX-M), which generally hydrolyzes cefotaxime (92 %) more than it does ceftazidime; followed by temoneira (TEM, 39 %); sulfhydryl variable (SHV, 5 %), and Vietnamese extended-spectrum beta–lactamase (VEB, 1.6 %). Conclusion: A high prevalence of aac(6')-Ib-cr ...

  7. Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

    African Journals Online (AJOL)

    Erah

    PMQR) genes and the prevalence of extended spectrum β-lactamase (ESBL) types in Escherichia coli clinical isolates. Methods: Sixty-one ESBL-producing urinary E. coli isolates were studied. An antibiotic susceptibility test was performed ...

  8. Plasmid mediated enhancement of uv resistance in Streptococcus faecalis

    International Nuclear Information System (INIS)

    Miehl, R.; Miller, M.; Yasbin, R.E.

    1980-01-01

    A 38.5-Mdal plasmid of Streptococcus faecalis subdp. zymogenes has been shown to enhance survival following uv irradiation. In addition, the presence of this plasmid increases the mutation frequencies following uv irradiation and enhanced W-reactivation. The data presented indicate that S. faecalis has an inducible error-prone repair system and that the plasmid enhances these repair functions

  9. Factors influencing the survival and leaching of tetracycline-resistant bacteria and Escherichia coli through structured agricultural fields

    DEFF Research Database (Denmark)

    Bech, Tina B.; Rosenbom, Annette E.; Kjaer, Jeanne

    2014-01-01

    Intense use of antibiotics in agricultural production may lead to the contamination of surface and groundwater by antibiotic-resistant bacteria. In the present study, the survival and leaching of E. coli and tetracycline-resistant bacteria were monitored at two well-structured agricultural fields...

  10. Application of manure containing tetracyclines slowed down the dissipation of tet resistance genes and caused changes in the composition of soil bacteria.

    Science.gov (United States)

    Xiong, Wenguang; Wang, Mei; Dai, Jinjun; Sun, Yongxue; Zeng, Zhenling

    2018-01-01

    Manure application contributes to the increased environmental burden of antibiotic resistance genes (ARGs). We investigated the response of tetracycline (tet) resistance genes and bacterial taxa to manure application amended with tetracyclines over two months. Representative tetracyclines (oxytetracycline, chlorotetracycline and doxycycline), tet resistance genes (tet(M), tet(O), tet(W), tet(S), tet(Q) and tet(X)) and bacterial taxa in the untreated soil, +manure, and +manure+tetracyclines groups were analyzed. The abundances of all tet resistance genes in the +manure group were significantly higher than those in the untreated soil group on day 1. The abundances of all tet resistance genes (except tet(Q) and tet(X)) were significantly lower in the +manure group than those in the +manure+tetracyclines group on day 30 and 60. The dissipation rates were higher in the +manure group than those in the +manure+tetracyclines group. Disturbance of soil bacterial community composition imposed by tetracyclines was also observed. The results indicated that tetracyclines slowed down the dissipation of tet resistance genes in arable soil after manure application. Application of manure amended with tetracyclines may provide a significant selective advantage for species affiliated to the taxonomical families of Micromonosporaceae, Propionibacteriaceae, Streptomycetaceae, Nitrospiraceae and Clostridiaceae. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes

    Science.gov (United States)

    You, Y.; Ball, W. P.; Ward, M. J.; Hilpert, M.

    2007-12-01

    Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (ECa) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of ECa and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (Tc\\tiny R), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of Tc\\tiny R bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated Tc\\tiny R genes and to explore a link between the presence of Tc\\tiny R and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent Tc\\tiny R gene. This gene will be monitored in future experiments, in which we will study the transmission of Tc\\tiny R to naive E.~coli under selective pressure of Tc. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.

  12. Survival and leaching of Tetracycline resistant bacteria and fecal indicators from manure in field scale experiments

    DEFF Research Database (Denmark)

    Bech, Tina; Amin, Mostofa; Lægdsmand, Mette

    The spreading of manure on agricultural land is an economic and practical solution for improving soil quality; however, animal manure frequently contains zoonotic pathogenic bacteria, such as certain Eschericia coli, Salmonella spp. and Campylobacter spp. The present experiment was conducted...... as a large multidisciplinary project. Pig manure with a natural content of Tetracycline resistant bacteria and fecal indicator organisms was followed in soil columns and a field scale experiment. In the field experiment pig manure was injected into agricultural soil. The distribution and survival of natural...... occurring indicator bacteria around a manure slurry slit in the soil was followed. During a period of two months, sections of soils with different distance to the manure string were assayed to obtain information on survival and spread of bacteriophage, faecal indicators (Enterococci, Bacterioides, E. coli...

  13. Identification of Tet 39, a novel class of tetracycline resistance determinant in Acinetobacter spp. of environmental and clinical origin

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Guardabassi, L.

    2005-01-01

    A novel tetracycline resistance determinant named Tet 39 was found in unrelated Acinetobacter strains isolated from freshwater trout farms (n=4) and sewage (n=6) in Denmark, and from a clinical specimen in the Netherlands (n=1). The determinant was located on transferable plasmids and consisted o...

  14. Effect of tetracycline dose and treatment-mode on selection of resistant coliform bacteria in nursery pigs

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders

    2017-01-01

    This study describes results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on selection of antibiotic resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4-7 weeks of age) were treated...... with oxytetracycline against Lawsonia intracellularis induced diarrhea in five pig herds. Each group was randomly allocated to one of five treatment groups: oral flock treatment with (i) high (20 mg/kg), (ii) medium (10 mg/kg) and (iii) low (5 mg/kg) dosage, (iv) oral-pen-wise (small group) treatment (10 mg...... significant changes in number or proportion of tetracycline resistant coliforms. Selection for tetracycline-resistant coliforms was significantly correlated to selection for ampicillin- and sulfonamide-resistant, but not to cefotaxime-resistant strains. In conclusion, difference in dose of oxytetracycline...

  15. Class 1 integrons and tetracycline resistance genes in Alcaligenes, Arthrobacter, and Pseudomonas spp. isolated from pigsties and manured soil

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Sandvang, Dorthe

    2005-01-01

    The presence of tetracycline resistance (Tc-r) genes and class I integrons (in-1), and their ability to cotransfer were investigated in Tc-r gram-negative (185 strains) and gram-positive (72 strains) bacteria from Danish farmland and pigsties. The isolates belonged to the groups or species...... tet(33). No isolates contained more than one tet gene. The in-l-positive isolates were tested for resistance to selected antimicrobial agents and showed resistance to three to nine drugs. Filter-mating experiments showed cotransfer of Tc-r and class I integrons from soil isolates to Escherichia coli...... and/or Pseudomonas putida. We conclude that soil bacteria in close contact to manure or pigsty environment may thus have an important role in horizontal spread of resistance. Use of tetracyclines in food animal production may increase not only Tc-r but also multidrug resistance (caused by the presence...

  16. A Simple Model of Tetracycline Antibiotic Resistance in the Aquatic Environment (with Application to the Poudre River

    Directory of Open Access Journals (Sweden)

    Sarah Sanchez

    2011-02-01

    Full Text Available Antibiotic resistance is a major concern, yet it is unclear what causes the relatively high densities of resistant bacteria in the anthropogenically impacted environment. There are various possible scenarios (hypotheses: (A Input of resistant bacteria from wastewater and agricultural sources is significant, but they do not grow in the environment; (B Input of resistant bacteria is negligible, but the resistant bacteria (exogenous or endogenous grow due to the selection pressure of the antibiotic; (C Exogenous bacteria transfer the resistance to the endogenous bacteria and those grow. This paper presents a simple mechanistic model of tetracycline resistance in the aquatic environment. It includes state variables for tetracyclines, susceptible and resistant bacteria, and particulate and dissolved organic matter in the water column and sediment bed. The antibiotic partitions between freely dissolved, dissolved organic matter (DOM-bound and solids-bound phases, and decays. Bacteria growth is limited by DOM, inhibited by the antibiotic (susceptible bacteria only and lower due to the metabolic cost of carrying the resistance (resistant bacteria only. Resistant bacteria can transfer resistance to the susceptible bacteria (conjugation and lose the resistance (segregation. The model is applied to the Poudre River and can reproduce the major observed (literature data patterns of antibiotic concentration and resistance. The model suggests observed densities of resistant bacteria in the sediment bed cannot be explained by input (scenario A, but require growth (scenarios B or C.

  17. Metagenomic insights into tetracycline effects on microbial community and antibiotic resistance of mouse gut.

    Science.gov (United States)

    Yin, Jinbao; Zhang, Xu-Xiang; Wu, Bing; Xian, Qiming

    2015-12-01

    Antibiotics have been widely used for disease prevention and treatment of the human and animals, and for growth promotion in animal husbandry. Antibiotics can disturb the intestinal microbial community, which play a fundamental role in animals' health. Misuse or overuse of antibiotics can result in increase and spread of microbial antibiotic resistance, threatening human health and ecological safety. In this study, we used Illumina Hiseq sequencing, (1)H nuclear magnetic resonance spectroscopy and metagenomics approaches to investigate intestinal microbial community shift and antibiotic resistance alteration of the mice drinking the water containing tetracycline hydrochloride (TET). Two-week TET administration caused reduction of gut microbial diversity (from 194 to 89 genera), increase in Firmicutes abundance (from 24.9 to 39.8%) and decrease in Bacteroidetes abundance (from 69.8 to 51.2%). Metagenomic analysis showed that TET treatment affected the intestinal microbial functions of carbohydrate, ribosomal, cell wall/membrane/envelope and signal transduction, which is evidenced by the alteration in the metabolites of mouse serum. Meanwhile, in the mouse intestinal microbiota, TET treatment enhanced the abundance of antibiotic resistance genes (ARGs) (from 307.3 to 1492.7 ppm), plasmids (from 425.4 to 3235.1 ppm) and integrons (from 0.8 to 179.6 ppm) in mouse gut. Our results indicated that TET administration can disturb gut microbial community and physiological metabolism of mice, and increase the opportunity of ARGs and mobile genetic elements entering into the environment with feces discharge.

  18. Chemosensitization of Trypanosoma congolense strains resistant to isometamidium chloride by tetracyclines and enrofloxacin.

    Directory of Open Access Journals (Sweden)

    Vincent Delespaux

    Full Text Available BACKGROUND: Because of the development of resistance in trypanosomes to trypanocidal drugs, the livelihood of millions of livestock keepers in sub-Saharan Africa is threatened now more than ever. The existing compounds have become virtually useless and pharmaceutical companies are not keen on investing in the development of new trypanocides. We may have found a breakthrough in the treatment of resistant trypanosomal infections, through the combination of the trypanocide isometamidium chloride (ISM with two affordable veterinary antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: In a first experiment, groups of mice were inoculated with Trypanosoma congolense strains resistant to ISM and either left untreated or treated with (i tetracycline, (ii ISM or (iii the combination of the antibiotic and the trypanocide. Survival analysis showed that there was a significant effect of treatment and resistance to treatment on the survival time. The groups treated with ISM (with or without antibiotic survived significantly longer than the groups that were not treated with ISM (P<0.01. The group treated with the combination trypanocide/antibiotic survived significantly longer than the group treated with ISM (P<0.01. In a second experiment, groups of cattle were inoculated with the same resistant trypanosome strain and treated with (i ISM, (ii ISM associated with oxytetracycline or (iii ISM associated with enrofloxacine. All animals treated with ISM became parasitaemic. In the groups treated with ISM-oxytetracycline and ISM-enrofloxacine, 50% of the animals were cured. Animals from the groups treated with a combination trypanocide/antibiotic presented a significantly longer prepatent period than animals treated with ISM (p<0.001. The impact of the disease on the haematocrit was low in all ISM treated groups. Yet, it was lower in the groups treated with the combination trypanocide/antibiotic (p<0.01. CONCLUSIONS/SIGNIFICANCE: After optimization of the administration

  19. PCR detection of oxytetracycline resistance genes otr(A) and otr(B) in tetracycline-resistant streptomycete isolates from diverse habitats

    NARCIS (Netherlands)

    Nikolakopoulou, T; Egan, S; van Overbeek, L; Guillaume, G; Heuer, H; Wellington, EMH; van Elsas, JD; Collard, JM; Smalla, K; Karagouni, A

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (Tc-R) streptomycete isolates from

  20. Occurrence of tetracycline resistance genes in aquaculture facilities with varying use of oxytetracycline

    Science.gov (United States)

    Seyfried, Erin E.; Newton, Ryan J.; Rubert, Kennedy F.; Pedersen, Joel A.; McMahon, Katherine D.

    2014-01-01

    The contribution of human activities to environmental reservoirs of antibiotic resistance is poorly understood. The purpose of this study was to determine if oxytetracycline (OTC) use in aquaculture facilities increased the detection frequency (i.e. prevalence) of tetracycline resistance genes relative to facilities with no recent OTC treatment. We used PCR to screen water and sediment from four non-commercial fish farms in northwestern Wisconsin for the presence of ten tetracycline resistance determinants (tetR): tet(A), tet(B), tet(D), tet(E), tet(G), tet(M), tet(O), tet(Q), tet(S) and tet(W). Water from farms with recent OTC use had significantly higher tetR detection frequencies than did water from farms without recent OTC use, with prevalence in raceways and rearing ponds of farms with recent OTC use exceeded by more than two-fold that of farms not using OTC. Effluent from all farms, regardless of treatment regime, had higher tetR detection frequencies than their corresponding influent for all genes, but the specific combinations of tetR genes detected in a sample were not different from their corresponding influent. Although OTC use was associated with the increased occurrence and diversity of tetR genes in water samples, it was not found to relate to tetR gene occurrence in sediment samples. Sediment samples from facilities with no recent OTC use had significantly higher frequencies of tetR gene detection than did samples from facilities with recent OTC use. All of the tetR genes were detected in both the medicated and non-medicated feed samples analyzed in this study. These findings suggest that both OTC treatment in aquaculture facilities, and the farms themselves, may be sources of tetR gene introduction to the environment. To our knowledge, this is the first study to use genotypic and cultivation-independent methods to examine tetR gene occurrence associated with OTC use in aquaculture. PMID:20217406

  1. The Gut as Reservoir of Antibiotic Resistance: Microbial Diversity of Tetracycline Resistance in Mother and Infant

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Valles, Yvonne; Agersø, Yvonne

    2011-01-01

    The microbiota in the human gastrointestinal tract (GIT) is highly exposed to antibiotics, and may be an important reservoir of resistant strains and transferable resistance genes. Maternal GIT strains can be transmitted to the offspring, and resistances could be acquired from birth. This is a ca...

  2. Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products.

    Science.gov (United States)

    Zycka-Krzesinska, Joanna; Boguslawska, Joanna; Aleksandrzak-Piekarczyk, Tamara; Jopek, Jakub; Bardowski, Jacek K

    2015-10-15

    To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Prevalence of tetracycline resistance and genotypic analysis of populations of Escherichia coli from animals, carcasses and cuts processed at a pig slaughterhouse

    DEFF Research Database (Denmark)

    Shuyu, Wu; Dalsgaard, Anders; Vieira, Antonio R

    2009-01-01

    A Danish pig slaughterhouse was visited in this study to investigate the impact of carcass processing on prevalence of tetracycline-resistant Escherichia coli, and to identify the origins of carcass contaminations with E. coli by assessing genetic diversity of E. coli populations on carcasses....... A total of 105 carcasses were sampled at five sequential stages: after stunning, after scalding, after splitting, after cooling and after cutting. Total and tetracycline-resistant E. coli were counted for each sample and tetracycline resistance prevalence per sample was calculated by the fraction...... of tetracycline-resistant E. coli out of total E. coli. From 15 repeatedly sampled carcasses, 422 E. coli isolates from faeces, stunned carcasses, split carcasses and chilled carcasses were examined by pulse-field gel electrophoresis (PFGE) and tested for antimicrobial susceptibility. The results showed that E...

  4. Regulation of the pT181 encoded tetracycline resistance gene in Straphylococcus aureus

    International Nuclear Information System (INIS)

    Mojumdar, M.

    1986-01-01

    pT181 is a naturally-occurring 4437 basepair (bp) plasmid isolated from Staphylococcus aureus which encodes inducible resistance to tetracycline (Tc). The DNA sequence data has identified three open reading frames (ORFs). The largest ORF B, has been found to be responsible for the Tc resistance phenotype of pT181. Since most Tc resistance systems appear to be regulated by an effector protein and a repressor protein, several Bal 31 deletion mutants of pT181 were constructed and analyzed in an effort to identify the elements involved in Tc resistance. Two transcomplementing groups of mutants were identified within the tet gene. The mechanism of Tc resistance was studied by assaying the accumulation of [7- 3 H] Tc by Tc sensitive cells, and uninduced and induced pT181-containing cells. A sharp decrease in accumulation of the drug after an initial increase was observed in Tc induced pT181-containing cells. In vivo labeling of Bacillus subtilis minicells containing pT181 was performed with 35 S-methionine to identify the polypeptide product of the tet gene. A Tc-inducible protein having a molecular weight of approximately 50,000 daltons was detected only in B. subtilis minicells carrying pT181. Cell fractionation studies of S. aureus cells with and without pT181 showed that an approximately 28,000 daltons Tc-inducible protein was present in membranes of pT181 containing cells. The amount of TET protein in Tc induced minicells was about fifteen-fold higher than that in uninduced minicells. RNA prepared from stationary phase cells analyzed by Northern blot hybridization showed that the steady-state level of the tet mRNA in induced pT181-containing cells was bout four-fold higher than that in uninduced pT181-containing cells. When RNA synthesis was blocked with rifampicin, tet mRAN was found to be much more stable in Tc induced cells as compared to that in uninduced cells over a 30 min period

  5. A localized outbreak of cholera due to vibrio cholerae, ogawa resistant to tetracyclines

    International Nuclear Information System (INIS)

    Ahmed, S.

    2015-01-01

    To study the clinical and laboratory parameters of a localized Cholera outbreak and determine the sensitivity pattern of the subtype involved. Study Design: A descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore. Duration of Study: Two weeks. Patients and Methods: The study is about a localized outbreak of cholera in a group of soldiers, who consumed water from a single contaminated source of water. We are presenting here an account of the clinical and laboratory parameters of 39 hospitalized cases of cholera, who presented with profuse watery diarrhoea and vomiting. There vital signs, hydration status and systemic examination findings were recorded. Stool samples were sent for routine and microscopic examination and bacteriological culture. Blood samples were taken for complete blood count, serum sodium, potassium, urea and creatinine examination. SPSS 18 was used for statistical analysis of the results. Results: The average age of thirty nine men studied in this outbreak was 24.9 ± 6.9 years. There was no statistically significant difference between confirmed and suspected cholera cases on descriptive analysis of the clinical and laboratory parameters. Majority of patients showed pre-renal azotemia which improved within 48 to 72 hours of hospitalization. Stool cultures isolated Vibrio cholerae, subtype Ogawa, which was resistant to tetracyclines, cotrimoxazole and nalidixic acid but sensitive to fluoroquinolones and third generation cephalosporins. The outbreak was controlled when the contaminated water source was sealed and rectified. Conclusion: Multiple drug resistance strains of Vibrio cholera are causing large outbreaks which should be controlled by prevention of the disease and avoiding inappropriate use of antibiotics. (author)

  6. Multiplex PCR Study of Plasmid-Mediated AmpC Beta-Lactamases Genes in Clinical Isolates of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Maryam Dehghani

    2017-02-01

    Full Text Available Background:   AmpC β-lactamases are important cephalosporinases chromosomally encoded in many of Enterobacteriaceae and a few other organisms where they mediate resistance to cephalothin, cefazolin, cefoxitin and penicillins. The six different families of plasmid-mediated AmpC β-lactamases have been described, but no phenotypic test can discriminate among them. AmpC multiplex PCR has been successfully used to discriminate plasmid-mediated ampC specific families in organisms such as Klebsiella pneumonia and Escherichia coli. The aim of this study was to indicate the prevalence of AmpC β-lactamase genes by specifically designed primers through PCR test.Methods:   243 total clinical urine samples were collected, and 227 isolates were identified as Escherichia coli based on standard biochemical tests. Subsequently, the isolates were screened by disc diffusion and combined disc test for β-lactamase production. Resistant isolates were evaluated by PCR for ampC family determination. Results:  Antibiotic resistance pattern were observed as follows: cefepime (%25, ceftazidime (%31, ceftriaxone (%37, cefotaxime (%38. The ratio of isolates was detected as ESBLs and AmpC producers were 34% and 5.2%, respectively. PCR performed on 12 selected isolates via phenotypic tests and the results revealed that among 12 isolates, 11 contained blaCMY-42. Conclusion:  Unfortunately, antibiotic resistance has become an increasingly critical problem in many countries like Iran and occurrence of isolates co-expressing AmpC-β-lactamases and ESBLs can create serious problems in the future. As antibiotic options in the treatment of AmpC β-lactamases and ESBLs producing organisms are extremely limited, molecular screening by laboratories is suggested to reduce the risk of therapeutic defeat.

  7. Susceptibility of Escherichia coli and Enterococcus faecium isolated from pigs and broiler chickens to tetracycline degradation products and distribution of tetracycline resistance determinants in E-coli from food animals

    DEFF Research Database (Denmark)

    Sengeløv, G.; Halling-Sørensen, B.; Aarestrup, Frank Møller

    2003-01-01

    of tet(A) and tet(B) applied to all three animal species, and there was no difference between the distribution of tet(A) and tet(B) genes among non-pathogenic and pathogenic E. coli in any of the animal species. The susceptibility of 20 of these isolates together with 10 tetracycline sensitive E. coli......-anhydrochlortetracycline. In general both the tetracycline resistant and susceptible E. faecium were more susceptible to the compounds tested than E. coli. (C) 2003 Elsevier B.V.. All rights reserved....

  8. Detection and coexistence of six categories of resistance genes in Escherichia coli strains from chickens in Anhui Province, China

    Directory of Open Access Journals (Sweden)

    Lin Li

    2015-12-01

    Full Text Available The aim of this study was to characterise the prevalence of class 1 integrons and gene cassettes, tetracycline-resistance genes, phenicol-resistance genes, 16S rRNA methylase genes, extended-spectrum β-lactamase genes and plasmid-mediated fluoroquinolone resistance determinants in 184 Escherichia coli isolates from chickens in Anhui Province, China. Susceptibility to 15 antimicrobials was determined using broth micro-dilution. Polymerase chain reaction and DNA sequencing were used to characterise the molecular basis of the antibiotic resistance. High rates of antimicrobial resistance were observed; 131 out of the 184 (72.3% isolates were resistant to at least six antimicrobial agents. The prevalences of class 1 integrons, tetracycline-resistance genes, phenicol-resistance genes, 16S rRNA methylase genes, extended-spectrum β-lactamase genes and plasmid-mediated fluoroquinolone resistance determinants were 49.5, 17.4, 15.8, 0.5, 57.6 and 46.2%, respectively. In 82 isolates, 48 different kinds of coexistence of the different genes were identified. Statistical (χ2 analysis showed that the resistance to amoxicillin, doxycycline, florfenicol, ofloxacin and gentamicin had significant differences (P<0.01 or 0.01resistance genes, which showed a certain correlation between antimicrobial resistance and the presence of resistance genes.

  9. Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Yinfang Shen

    2018-03-01

    Full Text Available Streptococcus pyogenes, also known as group A Streptococcus (GAS, is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ non-susceptibility in Shanghai, China. GAS (n = 2,258 recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258, with the phenotype more prevalent in GAS isolated from adults (14.3% than from children (1.2%. Eighty percent (24/30 of FQ-non-susceptible isolates were also resistant to both macrolides (ermB and tetracycline (tetM including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152 of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12 were macrolide and tetracycline resistant

  10. The involvement of tetA and tetE tetracycline resistance genes in plasmid and chromosomal resistance of Aeromonas in Brazilian strains

    Directory of Open Access Journals (Sweden)

    Ilana Teruszkin Balassiano

    2007-11-01

    Full Text Available This study analyzed the involvement of tetA and tetE genes in the tetracycline resistance of 16 strains of genus Aeromonas, isolated from clinical and food sources. Polymerase chain reactions revealed that 37.5% of the samples were positive for tetA, and also 37.5% were tetE positive. One isolate was positive for both genes. Only the isolate A. caviae 5.2 had its resistance associated to the presence of a plasmid, pSS2. The molecular characterization of pSS2 involved the construction of its restriction map and the determination of its size. The digestion of pSS2 with HindIII originated two fragments (A and B that were cloned separately into the pUC18 vector. The tetA gene was shown to be located on the HindIII-A fragment by PCR. After transforming a tetracycline-sensitive strain with pSS2, the transformants expressed the resistance phenotype and harbored a plasmid whose size was identical to that of pSS2. The results confirmed the association between pSS2 and the tetracycline resistance phenotype, and suggest a feasible dissemination of tetA and tetE among strains of Aeromonas. This study suggests the spreading tetA and tetE genes in Aeromonas in Brazil and describes a resistance plasmid that probably contributes to the dissemination of the resistance.

  11. Molecular epidemiology, antimicrobial susceptibilities and resistance mechanisms of Streptococcus pyogenes isolates resistant to erythromycin and tetracycline in Spain (1994–2006

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    Rubio-López Virginia

    2012-09-01

    Full Text Available Abstract Background Group A Streptococcus (GAS causes human diseases ranging in severity from uncomplicated pharyngitis to life-threatening necrotizing fasciitis and shows high rates of macrolide resistance in several countries. Our goal is to identify antimicrobial resistance in Spanish GAS isolates collected between 1994 and 2006 and to determine the molecular epidemiology (emm/T typing and PFGE and resistance mechanisms of those resistant to erythromycin and tetracycline. Results Two hundred ninety-five out of 898 isolates (32.8% were erythromycin resistant, with the predominance of emm4T4, emm75T25, and emm28T28, accounting the 67.1% of the 21 emm/T types. Spread of emm4T4, emm75T25 and emm28T28 resistant clones caused high rates of macrolide resistance. The distribution of the phenotypes was M (76.9%, cMLSB (20.3%, iMLSB (2.7% with the involvement of the erythromycin resistance genes mef(A (89.5%, msr(D (81.7%, erm(B (37.3% and erm(A (35.9%. Sixty-one isolates were tetracycline resistant, with the main representation of the emm77T28 among 20 emm/T types. To note, the combination of tet(M and tet(O tetracycline resistance genes were similar to tet(M alone reaching values close to 40%. Resistance to both antibiotics was detected in 19 isolates of 7 emm/T types, being emm11T11 and the cMLSB phenotype the most frequent ones. erm(B and tet(M were present in almost all the strains, while erm(A, mef(A, msr(D and tet(O appeared in less than half of them. Conclusions Spanish GAS were highly resistant to macrolides meanwhile showed minor resistance rate to tetracycline. A remarkable correlation between antimicrobial resistance and emm/T type was noticed. Clonal spread of emm4T4, emm75T25 and emm28T28 was the main responsable for macrolide resistance where as that emm77T28 clones were it to tetraclycline resistance. A wide variety of macrolide resistance genes were responsible for three macrolide resistance phenotypes.

  12. Horizontal Transfer of Tetracycline Resistance Genes in the Subsurface of a Poultry Farm

    Science.gov (United States)

    You, Y.; Ward, M.; Hilpert, M.

    2008-12-01

    Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoirs of antibiotic resistant bacteria and antibiotic resistance genes. At a poultry farm, we, together with Mr.~James Doolittle from USDA, measured the apparent subsurface electrical conductivity (ECa) using a EM38 meter. The resulting ECaR) associated with the poultry farm due to the fact that tetracycline (Tc) is one of the most frequently used antibiotics in food animal production and therefore is probably used at this farm. Soil and aquifer samples were taken from the farm. TcR bacteria were detected, with higher concentrations in the top layer of soil than in the aquifer. TcR bacteria were then enriched from a soil sample, and two classes of TcR genes were detected: tet(M) genes encoding ribosomal protection proteins and tet(L) genes encoding tet efflux pumps. Sequences of the PCR products were compared to known tet(M) and tet(L) genes in GenBank using BLASTN. Phylogenetic trees were also built based on the sequence information. The tet(M) genes found in our soil sample were highly similar to those located on transposons. In a soil microcosm experiment, we used the aforementioned soil sample as incubation medium as well as genetic donor (TcR soil bacteria), and a green fluorescent strain of E. coli as a model genetic recipient to study horizontal transfer of TcR genes from soil bacteria to naïve bacteria. Concentrations of inoculated E. coli were continuously monitored for 15 days, TcR E. coli isolated, and colony PCR performed. The tet(M) genes were found to be transferred to naïve E. coli. The highest horizontal transfer ratio, 0.62 transconjugant per recipient, was observed when Tc was supplemented to a soil microcosm at a concentration of 140 μg/kg soil. Modeling is also ongoing to obtain a better understanding of this complex phenomenon.

  13. Detection and linkage to mobile genetic elements of tetracycline resistance gene tet(M) in Escherichia coli isolates from pigs

    DEFF Research Database (Denmark)

    Jurado-Rabadan, Sonia; de la Fuente, Ricardo; Ruiz-Santa-Quiteria, Jose A.

    2014-01-01

    Background: In Escherichia coli the genes involved in the acquisition of tetracycline resistance are mainly tet(A) and tet(B). In addition, tet(M) is the most common tetracycline resistance determinant in enterococci and it is associated with conjugative transposons and plasmids. Although tet......(M) has been identified in E. coli, to our knowledge, there are no previous reports studying the linkage of the tet(M) gene in E. coli to different mobile genetic elements. The aim of this study was to determine the occurrence of tet(A), tet(B), and tet(M) genes in doxycycline-resistant E. coli isolates...... from pigs, as well as the detection of mobile genetic elements linked to tet(M) in E. coli and its possible transfer from enterococci. Results: tet(A) was the most frequently detected gene (87.9%) in doxycycline-resistant isolates. tet(M) was found in 13.1% E. coli isolates. The tet(M) gene...

  14. Gallic acid-based indanone derivative interacts synergistically with tetracycline by inhibiting efflux pump in multidrug resistant E. coli.

    Science.gov (United States)

    Dwivedi, Gaurav Raj; Tiwari, Nimisha; Singh, Aastha; Kumar, Akhil; Roy, Sudeep; Negi, Arvind Singh; Pal, Anirban; Chanda, Debabrata; Sharma, Ashok; Darokar, Mahendra P

    2016-03-01

    The purpose of the present study was to study the synergy potential of gallic acid-based derivatives in combination with conventional antibiotics using multidrug resistant cultures of Escherichia coli. Gallic acid-based derivatives significantly reduced the MIC of tetracycline against multidrug resistant clinical isolate of E. coli. The best representative, 3-(3',4,'5'-trimethoxyphenyl)-4,5,6-trimethoxyindanone-1, an indanone derivative of gallic acid, was observed to inhibit ethidium bromide efflux and ATPase which was also supported by in silico docking. This derivative extended the post-antibiotic effect and decreased the mutation prevention concentration of tetracycline. This derivative in combination with TET was able to reduce the concentration of TNFα up to 18-fold in Swiss albino mice. This derivative was nontoxic and well tolerated up to 300 mg/kg dose in subacute oral toxicity study in mice. This is the first report of gallic acid-based indanone derivative as drug resistance reversal agent acting through ATP-dependent efflux pump inhibition.

  15. Transferability of a tetracycline resistance gene from probiotic Lactobacillus reuteri to bacteria in the gastrointestinal tract of humans.

    Science.gov (United States)

    Egervärn, Maria; Lindmark, Hans; Olsson, Johan; Roos, Stefan

    2010-02-01

    The potential of Lactobacillus reuteri as a donor of antibiotic resistance genes in the human gut was investigated by studying the transferability of the tetracycline resistance gene tet(W) to faecal enterococci, bifidobacteria and lactobacilli. In a double-blind clinical study, seven subjects consumed L. reuteri ATCC 55730 harbouring a plasmid-encoded tet(W) gene (tet(W)-reuteri) and an equal number of subjects consumed L. reuteri DSM 17938 derived from the ATCC 55730 strain by the removal of two plasmids, one of which contained the tet(W) gene. Faecal samples were collected before, during and after ingestion of 5 x 10(8) CFU of L. reuteri per day for 14 days. Both L. reuteri strains were detectable at similar levels in faeces after 14 days of intake but neither was detected after a two-week wash-out period. After enrichment and isolation of tetracycline resistant enterococci, bifidobacteria and lactobacilli from each faecal sample, DNA was extracted and analysed for presence of tet(W)-reuteri using a real-time PCR allelic discrimination method developed in this study. No tet(W)-reuteri signal was produced from any of the DNA samples and thus gene transfer to enterococci, bifidobacteria and lactobacilli during intestinal passage of the probiotic strain was non-detectable under the conditions tested, although transfer at low frequencies or to the remaining faecal bacterial population cannot be excluded.

  16. The effect of production type and antimicrobial usage on the occurrence of tetracycline resistant E. coli in danish slaughter pig farms

    DEFF Research Database (Denmark)

    Struve, Tina; Vigre, Håkan; Wingstrand, Anne

    The Qualysafe project was initiated in 2007 to support and strengthen the sustainable production systems in Danish food production. One of the objectives of the epidemiological investigation was to find new methods to improve food safety in conventional as well as in alternative pig production sy...... of potential risk factors on the occurrence of antimicrobial resistance in animal production....... (organic, free range and conventional farms) was a risk factor for occurrence of antimicrobial resistance and Tetracycline usage was regarded as an intervening factor between production type and occurrence of antimicrobial resistance. Therefore, the effect of production type and Tetracycline usage...... was estimated in two separate models using logistic regression, taking into account the correlation of results obtained from the same farm. Among the 411 isolates, 129 was found resistant to Tetracycline (Organic: 10%, Free Range: 27 % Conventional: 39 %). Differences was seen in the consumption pattern among...

  17. Two Different Tetracycline Resistance Mechanisms, Plasmid-Carried tet(L) and Chromosomally Located Transposon-Associated tet(M), Coexist in Lactobacillus sakei Rits 9

    NARCIS (Netherlands)

    Ammor, M.S.; Gueimonde, M.; Danielsen, M.; Zagorec, M.; Hoek, van A.H.A.M.; Reyes-Gavilán, de los C.G.; Mayo, B.; Margolles, A.

    2008-01-01

    Lactobacillus sakei is extensively used as functional starter culture in fermented meat products. One of the safety criteria of a starter culture is the absence of potentially transferable antibiotic resistance determinants. However, tetracycline-resistant L. sakei strains have already been

  18. In vitro assay for the anti-Brucella activity of medicinal plants against tetracycline-resistant Brucella melitensis.

    Science.gov (United States)

    Motamedi, Hossein; Darabpour, Esmaeil; Gholipour, Mahnaz; Seyyed Nejad, Seyyed Mansour

    2010-07-01

    Brucellosis, a zoonosis caused by four species of brucella, has a high morbidity. Brucella melitensis is the main causative agent of brucellosis in both human and small ruminants. As an alternative to conventional antibiotics, medicinal plants are valuable resources for new agents against antibiotic-resistant strains. The aim of this study was to investigate the usage of native plants for brucellosis treatment. For this purpose, the anti-brucella activities of ethanolic and methanolic extracts of Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, Plantago ovata, Cordia myxa, and Crocus sativus were assessed. The activity against a resistant Br. melitensis strain was determined by disc diffusion method at various concentrations from 50-400 mg/ml. Antibiotic discs were also used as a control. Among the evaluated herbs, six plant (Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, and Crocus sativus) showed anti-brucella activity. Oliveria decumbens was chosen as the most effective plant for further studies. A tested isolate exhibited resistance to tetracycline, nafcillin, oxacillin, methicillin, and colistin. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for Oliveria decumbens against resistant Br. melitensis were the same (5 mg/ml), and for gentamicin they were both 2 mg/ml. Time-kill kinetics for a methanolic extract of Oliveria decumbens was 7 h whereas for an ethanolic extract it was 28 h. Also, Oliveria decumbens extracts showed a synergistic effect in combination with doxycycline and tetracycline. In general, the similar values of MIC and MBC for Oliveria decumbens suggest that these extracts could act as bactericidal agents against Br. melitensis. In addition to Oliveria decumbens, Crocus sativus and Salvia sclarea also had good anti-brucella activity and these should be considered for further study.

  19. In vitro assay for the anti-brucella activity of medicinal plants against tetracycline-resistant Brucella melitensis *

    Science.gov (United States)

    Motamedi, Hossein; Darabpour, Esmaeil; Gholipour, Mahnaz; Seyyed Nejad, Seyyed Mansour

    2010-01-01

    Brucellosis, a zoonosis caused by four species of brucella, has a high morbidity. Brucella melitensis is the main causative agent of brucellosis in both human and small ruminants. As an alternative to conventional antibiotics, medicinal plants are valuable resources for new agents against antibiotic-resistant strains. The aim of this study was to investigate the usage of native plants for brucellosis treatment. For this purpose, the anti-brucella activities of ethanolic and methanolic extracts of Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, Plantago ovata, Cordia myxa, and Crocus sativus were assessed. The activity against a resistant Br. melitensis strain was determined by disc diffusion method at various concentrations from 50–400 mg/ml. Antibiotic discs were also used as a control. Among the evaluated herbs, six plant (Salvia sclarea, Oliveria decumbens, Ferulago angulata, Vitex pseudo-negundo, Teucrium polium, and Crocus sativus) showed anti-brucella activity. Oliveria decumbens was chosen as the most effective plant for further studies. A tested isolate exhibited resistance to tetracycline, nafcillin, oxacillin, methicillin, and colistin. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for Oliveria decumbens against resistant Br. melitensis were the same (5 mg/ml), and for gentamicin they were both 2 mg/ml. Time-kill kinetics for a methanolic extract of Oliveria decumbens was 7 h whereas for an ethanolic extract it was 28 h. Also, Oliveria decumbens extracts showed a synergistic effect in combination with doxycycline and tetracycline. In general, the similar values of MIC and MBC for Oliveria decumbens suggest that these extracts could act as bactericidal agents against Br. melitensis. In addition to Oliveria decumbens, Crocus sativus and Salvia sclarea also had good anti-brucella activity and these should be considered for further study. PMID:20593515

  20. Expansion of plasmid mediated blaACT-2 among Pseudomonas aeruginosa associated with postoperative infection and its transcriptional response under cephalosporin stress.

    Directory of Open Access Journals (Sweden)

    Birson Ingti, Deepjyoti Paul, Anand Prakash Maurya

    2017-06-01

    Full Text Available Objectives: Organisms harboring multiple plasmid mediated β-lactamases are major concerns in nosocomial infections. Among these plasmid mediated β-lactamases, ACT (EBC family is a clinically important enzyme capable of hydrolyzing broad spectrum cephalosporins. Therefore, the present study was undertaken to determine the prevalence of ACT determinant along with other co-existing β-lactamase genes in P. aeruginosa strains. Methods: A total of 176 Pseudomonas isolates were phenotypically screened for the presence of AmpC β-lactamase by M3DET Method followed by Molecular detection using PCR assay. Transcriptional evaluation of blaACT-2 gene was analyzed by RT-PCR and its transferability was performed by transformation and conjugation. Results: Present study demonstrates the presence of ACT-2 allele among 12 strains of P. aeruginosa. Co-existence of other β-lactamase genes were encountered among ACT-2 harboring strains which includes CTX-M (n=2, SHV (n=3, TEM (n=2, VEB (n=2, OXA-10 (n=1, CIT (n=2 and DHA (n=3. Fingerprinting by REP PCR revealed the isolates harboring ACT-2 to be distinct and these isolates showed high resistance to expanded-spectrum cephalosporins and even to carbapenem group of drugs. This ACT-2 allele was encoded in the plasmid (L/M, FIA, FIB Inc. Group and conjugatively transferable. Transcriptional analysis revealed a significant increase in ACT-2 expression (483 fold when induced by ceftriaxone at 4 µg/ml followed by ceftazidime at 8 µg/ml (31 fold and cefotaxime 4 µg/ml (8 fold. Conclusion: In this study detection of ACT-2 plasmid mediated AmpC β-lactamase along with other β-lactamase genes in clinical isolates of P. aeruginosa represents a serious therapeutic challenge. Therefore, revision in antimicrobial policy is required for effective treatment of patients infected with pathogen expressing this mechanism. J Microbiol Infect Dis 2017; 7(2: 75-82

  1. Seasonal dynamics of tetracycline resistance gene transport in the Sumas River agricultural watershed of British Columbia, Canada.

    Science.gov (United States)

    Keen, Patricia L; Knapp, Charles W; Hall, Kenneth J; Graham, David W

    2018-07-01

    Environmental transport of contaminants that can influence the development of antibiotic resistance in bacteria is an important concern in the management of ecological and human health risks. Agricultural regions are locales where practices linked to food crop and livestock production can introduce contaminants that could alter the selective pressures for the development of antibiotic resistance in microbiota. This is important in regions where the use of animal manure or municipal biosolids as waste and/or fertilizer could influence selection for antibiotic resistance in pathogenic bacterial species. To investigate the environmental transport of contaminants that could lead to the development of antibiotic resistance in bacteria, a watershed with one of the highest levels of intensity of agricultural activity in Canada was studied; the Sumas River located 60 km east of Vancouver, British Columbia. This two-year assessment monitored four selected tetracycline resistance genes (tet(O), tet(M), tet(Q), tet(W)) and water quality parameters (temperature, specific conductivity, turbidity, suspended solids, nitrate, phosphate and chloride) at eight locations across the watershed. The tetracycline resistance genes (Tc r ) abundances in the Sumas River network ranged between 1.47 × 10 2 and 3.49 × 10 4  copies/mL and ranged between 2.3 and 6.9 copies/mL in a control stream (located far from agricultural activities) for the duration of the study. Further, Tc r abundances that were detected in the wet season months ranged between 1.3 × 10 3 and 2.29 × 10 4  copies/mL compared with dry season months (ranging between 0.6 and 31.2 copies/mL). Highest transport rates between 1.67 × 10 11 and 1.16 × 10 12  copies/s were observed in November 2005 during periods of high rainfall. The study showed that elevated concentrations of antibiotic resistance genes in the order of 10 2 -10 4  copies/mL can move through stream networks in an

  2. Phenotypic and genotypic bacterial antimicrobial resistance in liquid pig manure is variously associated with contents of tetracyclines and sulfonamides.

    Science.gov (United States)

    Hölzel, C S; Harms, K S; Küchenhoff, H; Kunz, A; Müller, C; Meyer, K; Schwaiger, K; Bauer, J

    2010-05-01

    Antibiotic residues as well as antibiotic-resistant bacteria in environmental samples might pose a risk to human health. This study aimed to investigate the association between antibiotic residues and bacterial antimicrobial resistance in liquid pig manure used as fertilizer. Concentrations of tetracyclines (TETs) and sulfonamides (SULs) were determined by liquid chromatography-mass spectrometry in 305 pig manure samples; antibiotic contents were correlated to the phenotypic resistance of Escherichia coli (n = 613) and enterococci (n = 564) towards up to 24 antibiotics. In 121 samples, the concentration of the TET resistance genes tet(M), tet(O) and tet(B) was quantified by real-time-PCR. TETs were found in 54% of the samples. The median sum concentration of all investigated TETs in the positive samples was 0.73 mg kg(-1). SULs were found with a similar frequency (51%) and a median sum concentration of 0.15 mg kg(-1) in the positive samples. Associated with the detection of TETs and/or SULs, resistance rates were significantly elevated for several substances - some of them not used in farm animals, e.g. chloramphenicol and synercid. In addition, multiresistant isolates were found more often in samples containing antibiotics. Analysis of the resistance genes tet(M) and tet(O) already showed a significant increase in their concentrations - but not in tet(B) - in the lowest range of total TET concentration. Mean tet(M) concentrations increased by the factor of 4.5 in the TET concentration range of 0.1-1 mg kg(-1), compared to negative manure samples. Antibiotic contamination of manure seems to be associated with a variety of changes in bacterial resistance, calling for a prudent use of antibiotics in farm animals. This study provides an interdisciplinary approach to assess antimicrobial resistance by combining the microbiological analysis of bacterial resistance with high quality chemical analysis of antibiotic residues in a representative number of environmental

  3. Comparison of ozone and thermal hydrolysis combined with anaerobic digestion for municipal and pharmaceutical waste sludge with tetracycline resistance genes.

    Science.gov (United States)

    Pei, Jin; Yao, Hong; Wang, Hui; Ren, Jia; Yu, Xiaohua

    2016-08-01

    Biosolids from wastewater treatment plant (WWTP) are environmental reservoirs of antibiotic resistance genes, which attract great concerns on their efficient treatments. Anaerobic digestion (AD) is widely used for sewage sludge treatment but its effectiveness is limited due to the slow hydrolysis. Ozone and thermal hydrolysis pre-treatment were employed to improve AD efficiency and reduce antibiotic-resistant genes in municipal and pharmaceutical waste sludge (MWS and PWS, respectively) in this study. Sludge solubilization achieved 15.75-25.09% and 14.85-33.92% after ozone and thermal hydrolysis, respectively. Both pre-treatments improved cumulative methane production and the enhancements were greater on PWS than MWS. Five tetracycline-resistant genes (tet(A), tet(G), tet(Q), tet(W), tet(X)) and one mobile element (intI1) were qPCR to assess pre-treatments. AD of pre-treated sludge reduced more tet genes than raw sludge for both ozonation and thermal hydrolysis in PWS and MWS. Thermal hydrolysis pre-treatment was more efficient than ozone for reduction after AD. Results of this study help support management options for reducing the spread of antibiotic resistance from biosolids. Copyright © 2016. Published by Elsevier Ltd.

  4. Influência do uso de enrofloxacina no desenvolvimento de resistência às quinolonas mediada por plasmídeos em Escherichia coli de vitelos [Selection of plasmid-mediated quinolone resistance in commensal E. coli by the use of enrofloxacin in calves

    DEFF Research Database (Denmark)

    Guerreiro, L.; Couto, N.; Centeno, M.

    O conhecimento existente sobre a presença e frequência de genes de Resistência às Quinolonas Mediada por Plasmídeos (RQMP) em estirpes comensais de E. coli de origem bovina é escasso a nível mundial. O presente trabalho teve como objectivos:i) avaliar a frequência de genes de RQMP, designadamente...... exista uma associação entre a presença de genes de RQMP e valores de CIMs, verifica-se um aumento da frequência destes genes ao longo do estudo longitudinal. Este é o primeiro estudo que descreve a existência de resistência às quinolonas por qQnrD em isolados de E. coli de bovinos....

  5. Determination of tetracycline resistance genes in Vibrio cholerae O1 biotype El Tor serotype Inaba strains isolated from outbreaks occurred in Iran in 2013

    Directory of Open Access Journals (Sweden)

    Azin Khany

    2016-05-01

    Full Text Available V. cholerae is the causative agent of potentially life threatening diarrheal disease named as cholera. Cholera is an endemic disease in Iran. Encountered increasing resistance of V. cholerae to commonly used antibiotics such as tetracycline has led to major challenges in the treatment of this disease .The present study was carried out to determine the prevalence of drug resistance as well as molecular bases of resistant V.cholerae strains which were isolated from patients in cholera outbreaks during summer of 2013 in Iran. Susceptibly testing was performed on V.cholerae strains isolated from stool of patients suffering from cholera in Iranian reference health laboratory by E -test MIC method as recommended by CLSI guideline. Antibiotic strips used included Ampicillin, Ciprofloxacin, Nalidixic acid, Cefixime , Tetracycline, Erythromycin and Trimethoprim-sulfamethoxazole .Regarding observed dominant pattern of tetracycline resistance comparing to results of previous years ,we decided to confirm the resistance by detecting the tetA , tetB and tetC by Polymerase chain reaction method. The results of antibiotic susceptibility testing revealed 100% resistance of isolated strains to tetracycline. Data obtained from PCR reaction on resistant strains for tetA, tetB and tetC showed that 45(44.1%, 37(36.2% and 70(68.6% were containing tetA, tetB and tetC gene respectively. Moreover, the frequency of tetA+tetB, tetA+C, tetB+tetC , tetA+tetB+tetC also were determined as 9(8.8%, 32(31.3%, 19(18.6% and 8(7.8% respectively. This study revealed the pattern of drug resistance distribution of isolates harboring tetA, tetB, tetC genes in relation to sex, age and nationality of patients and the cities where the cases were reported. A significant correlation was obtained between reported geographical incidence and drug resistant strains.

  6. Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

    Directory of Open Access Journals (Sweden)

    Jayasekara M. K. J. K. Premarathne

    2017-12-01

    Full Text Available Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100, beef (n = 120 from wet markets and beef (n = 120 from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR identified 55% of the strains as C. jejuni, 26% as C. coli, and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9% and ampicillin (69.2%, whilst low resistance was exhibited to chloramphenicol (7.6%. The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety.

  7. Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia.

    Science.gov (United States)

    Premarathne, Jayasekara M K J K; Anuar, Aimi S; Thung, Tze Young; Satharasinghe, Dilan A; Jambari, Nuzul Noorahya; Abdul-Mutalib, Noor-Azira; Huat, John Tang Yew; Basri, Dayang F; Rukayadi, Yaya; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

    2017-01-01

    Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces ( n = 100), beef ( n = 120) from wet markets and beef ( n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cattle fecal samples, 14.2% in raw beef from wet market and 7.5% in raw beef from the hypermarket. The multiplex-polymerase chain reaction (PCR) identified 55% of the strains as C. jejuni , 26% as C. coli , and 19% as other Campylobacter spp. A high percentage of Campylobacter spp. were resistant to tetracycline (76.9%) and ampicillin (69.2%), whilst low resistance was exhibited to chloramphenicol (7.6%). The MAR Index of Campylobacter isolates from this study ranged from 0.09 to 0.73. The present study indicates the potential public health risk associated with the beef food system, hence stringent surveillance, regulatory measures, and appropriate interventions are required to minimize Campylobacter contamination and prudent antibiotic usage that can ensure consumer safety.

  8. Sulfonamide and tetracycline resistance genes in total- and culturable-bacterial assemblages in South African aquatic environments

    Directory of Open Access Journals (Sweden)

    Satoru eSuzuki

    2015-08-01

    Full Text Available Antibiotic resistant bacteria (ARB are ubiquitous in the natural environment. The introduction of effluent derived antibiotic resistance genes (ARGs into aquatic environments is of concern in the spreading of genetic risk. This study showed the prevalence of sulfonamide and tetracycline resistance genes, sul1, sul2, sul3 and tet(M, in the total bacterial assemblage and colony forming bacterial assemblage in river and estuarine water and sewage treatment plants (STP in South Africa. There was no correlation between antibiotic concentrations and ARGs, suggesting the targeted ARGs are spread in a wide area without connection to selection pressure. Among sul genes, sul1 and sul2 were major genes in the total (over 10-2 copies/16S and colony forming bacteria assemblages (approx 10-1 copies/16S. In urban waters, the sul3 gene was mostly not detectable in total and culturable assemblages, suggesting sul3 is not abundant. tet(M was found in natural assemblages with 10-3 copies/16S level in STP, but was not detected in colony forming bacteria, suggesting the non-culturable (yet-to-be cultured bacterial community in urban surface waters and STP effluent possess the tet(M gene. Sulfamethoxazole resistant (SMXr and oxytetracycline resistant (OTCr bacterial communities in urban waters possessed not only sul1 and sul2 but also sul3 and tet(M genes. These genes are widely distributed in SMXr and OTCr bacteria. In conclusion, urban river and estuarine water and STP effluent in the Durban area were highly contaminated with ARGs, and the yet-to-be cultured bacterial community may act as a non-visible ARG reservoir in certain situations.

  9. Graphene oxide in the water environment could affect tetracycline-antibiotic resistance.

    Science.gov (United States)

    Guo, Mei-Ting; Zhang, Guo-Sheng

    2017-09-01

    In recent years, the influence of new materials like nanoparticles in the water environment on biological substances has been widely studied. Antibiotic resistance genes (ARGs) represent a new type of pollutant in the environment. Graphene oxide (GO), as a nano material, because of its unique structure, may have an impact on antibiotic resistance bacteria (ARB) and ARGs; however the research in this area is rarely reported. Therefore, this study mainly investigated the effects of GO on bacterial antibiotic resistance. The results showed that GO had a limited effect on ARB inactivation. A high concentration of GO (>10 mg/L) can damage resistant plasmids to reduce bacterial resistance to antibiotics, but low concentrations of GO (antibiotic resistance needs further investigation. Copyright © 2017. Published by Elsevier Ltd.

  10. The lactococcal secondary multidrug transporter LmrP confers resistance to lincosamides, macrolides, streptogramins and tetracyclines

    NARCIS (Netherlands)

    Putman, M; van Veen, HW; Degener, JE; Konings, WN

    2001-01-01

    The active efflux of toxic compounds by (multi)drug transporters is one of the mechanisms that bacteria have developed to resist cytotoxic drugs. The authors describe the role of the lactococcal secondary multidrug transporter LmrP in the resistance to a broad range of clinically important

  11. Tetracycline resistance genes persist in soil amended with cattle feces independently from chlortetracycline selection pressure

    NARCIS (Netherlands)

    Kyselkova, Martina; Kotrbova, Lucie; Bhumibhamon, Gamonsiri; Chronakova, Alica; Jirout, Jiri; Vrchotova, Nadezda; Schmitt, Heike; Elhottova, Dana

    Antibiotic residues and antibiotic resistance genes originating from animal waste represent environmental pollutants with possible human health consequences. In this study, we addressed the question whether chlortetracycline (CTC) residues in soils can act as selective pressure enhancing the

  12. Detection of plasmid-mediated AmpC β-lactamase in Escherichia coli and Klebsiella pneumoniae

    Directory of Open Access Journals (Sweden)

    N O Yilmaz

    2013-01-01

    Full Text Available Background: Detecting plasmid-mediated AmpC (pAmpC β-lactamase-producing organism is important for optimal infection control and providing accurate and effective treatment option for physicians. Objectives: The aim of this study was to investigate the prevalence of pAmpC β-lactamase and compare the results of boronic acid (BA disk test with other phenotypic tests detecting AmpC positive isolates. Materials and Methods: A total of 273 clinical isolates of Klebsiella pneumoniae (n: 82 and Escherichia coli (n: 191 were analysed. The presence of pAmpC β-lactamase was determined by BA disk test, cefoxitin (FOX screening test, modified three dimensional test (M3DT, and multiplex polymerase chain reaction (PCR. Pulsed-field gel electrophoresis was performed to evaluate the genetic similarities between isolates. To detect extended spectrum β-lactamases (ESBL in the presence of AmpC β-lactamase, ESBL confirmation test was carried out with and without BA solution. Results: Of the 273 strains tested, 127 strains were found FOX resistant, 114 were positive by M3DT, 108 were positive in BA disk test, and the multiplex PCR detected 24 pAmpC β-lactamase-positive isolate. The prevalence of AmpC-producing strains was 10.9% in E. coli and 3.6% in K. pneumoniae in the tested population by PCR. CIT and MOX group genes were predominant type in these strains. Conclusion: These results emphasize that clinical laboratories should consider testing the presence of pAmpC enzymes particularly in FOX-resistant isolates, and BA disk test will improve detection of this emerging resistance phenotype.

  13. Effect of tetracycline dose and treatment mode on selection of resistant coliform bacteria in nursery pigs

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Damborg, Peter; Mellerup, Anders

    2017-01-01

    This study describes the results of a randomized clinical trial investigating the effect of oxytetracycline treatment dose and mode of administration on the selection of antibiotic-resistant coliform bacteria in fecal samples from nursery pigs. Nursery pigs (pigs of 4 to 7 weeks of age) in five pig...... by the time that the pigs left the nursery unit. The counts and proportions of tetracyclineresistant coliforms did not vary significantly between treatment groups, except immediately after treatment, when the highest treatment dose resulted in the highest number of resistant coliforms. A control group treated...

  14. Characterization of microbial community and antibiotic resistance genes in activated sludge under tetracycline and sulfamethoxazole selection pressure

    International Nuclear Information System (INIS)

    Zhang, Yingying; Geng, Jinju; Ma, Haijun; Ren, Hongqiang; Xu, Ke; Ding, Lili

    2016-01-01

    To investigate the microbial community characteristics, antibiotic resistance genes (ARGs), and bioreactor effluent quality change under tetracycline (TC) and sulfamethoxazole (SMX) selection pressure, sequencing batch reactors (SBRs) were used with environmentally relevant concentration and high-level of TC and SMX concentrations (0, 5 ppb, 50 ppb and 10 ppm). Chemical oxygen demand (COD) and ammonia nitrogen (NH_4"+−N) removals appeared unchanged (p > 0.05) with 5 and 50 ppb, but decreased significantly with 10 ppm (p tetG > sul2 > tetA > intI1 > tetS > tetC. Pearson correlation analysis showed most ARGs (tetA, tetC, tetG, tetK, tetM, sul1) were significantly correlated with intI1 (p < 0.01). - Highlights: • COD and NH_4"+−N removals significantly decrease under 10 ppm TC or SMX. • Activated sludge EPS concentrations increase with increasing TC or SMX concentrations. • TC and SMX affect the microbial community diversity of activated sludge. • Actinobacteria abundances increase with increase of TC or SMX concentration. • ARGs abundance increases with addition of TC or SMX.

  15. [Tetracyclines, sulfonamides and metronidazole].

    Science.gov (United States)

    Pérez-Trallero, Emilio; Iglesias, Luis

    2003-11-01

    Tetracyclines form a group of natural and semisynthetic products that acts inhibiting the bacterial protein synthesis. They are bacteriostatic agents, exhibiting activity against a wide range of organisms, but they are at the present of limited use because of their acquired resistance. Doxycycline is currently the most frequently used tetracycline in human medicine and it is included in the List of Essential Medicines of the World Health Organization. Sulfonamides are synthetic, broad-spectrum bacteriostatic antibiotics. They were the first effective systemic antimicrobial agents. Their mode of action is based on the inhibition of DNA synthesis. Due to their toxicity and high adquired resistance their use is currently very low. Metronidazole is the main compound of 5-nitroimidazole family. It is a very active bactericidal antibiotic against anaerobic and some microaerophilic bacteria and it is still very useful in the treatment of bacterian and parasitic infections.

  16. Copresence of tet(K) and tet(M) in Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Is Associated with Increased Fitness during Exposure to Sublethal Concentrations of Tetracycline

    DEFF Research Database (Denmark)

    Larsen, Jesper; Clasen, Julie; Hansen, Julie Elvekjær

    2016-01-01

    The tetracycline resistance gene tet(K) was shown to be integrated within the predominant staphylococcal cassette chromosome mec (SCCmec) element of Danish livestock-associated methicillin-resistant Staphylococcus aureus CC398 (LA-MRSA CC398). These LA-MRSA CC398 isolates already possessed tet(M)......(M), but the acquisition of tet(K) significantly improved their fitness at sublethal concentrations of tetracycline. Because tet(K) is genetically linked to SCCmec, the use of tetracycline in food animals may have contributed to the successful spread of LA-MRSA CC398....

  17. Tetracycline-resistant Escherichia coli strains are inherited from parents and persist in the infant's intestines in the absence of selective pressure.

    Science.gov (United States)

    Prelog, Martina; Grif, Katharina; Decristoforo, Cornelia; Würzner, Reinhard; Kiechl-Kohlendorfer, Ursula; Brunner, Andrea; Zimmerhackl, Lothar Bernd; Orth, Dorothea

    2009-10-01

    The study investigated tetracycline (TC), ampicillin (AMP), cefazolin (CEF), and trimethoprim (TMP) resistance in Escherichia coli (E. coli) in the feces of 21 infants up to 6 months of age and in their parents in the absence of selective antimicrobial pressure. Clonality of strains was assessed by pulsed-field gel electrophoresis. Three infants had resistant E. coli strains in their feces identical to the mothers' from week 1 on, which persisted over weeks. From week 2 on, in another four infants, persisting resistant E. coli were found, two of them identical to the mothers'. All of these persisting E. coli strains (except one family) showed at least resistance to TC. In infants, resistant E. coli strains inherited from their mothers tended to persist over months. Therefore, the persistence of resistant E. coli and their possible capacity to cause symptomatic infection or transfer its resistance genes to other bacteria deserves more attention.

  18. Characterization of microbial community and antibiotic resistance genes in activated sludge under tetracycline and sulfamethoxazole selection pressure

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingying; Geng, Jinju, E-mail: jjgeng@nju.edu.cn; Ma, Haijun; Ren, Hongqiang; Xu, Ke; Ding, Lili

    2016-11-15

    To investigate the microbial community characteristics, antibiotic resistance genes (ARGs), and bioreactor effluent quality change under tetracycline (TC) and sulfamethoxazole (SMX) selection pressure, sequencing batch reactors (SBRs) were used with environmentally relevant concentration and high-level of TC and SMX concentrations (0, 5 ppb, 50 ppb and 10 ppm). Chemical oxygen demand (COD) and ammonia nitrogen (NH{sub 4}{sup +}−N) removals appeared unchanged (p > 0.05) with 5 and 50 ppb, but decreased significantly with 10 ppm (p < 0.05). Extracellular polymeric substances (EPS) concentrations increased significantly with increasing TC or SMX concentrations (p < 0.05). High-throughput 16S rRNA gene sequencing results suggested that Proteobacteria, Actinobacteria and Bacteroidetes were the three most abundant phyla in sludge samples. The Actinobacteria percentages increased with increasing TC or SMX concentration, while Proteobacteria and Bacteroidetes decreased. The microbial diversity achieved its maximum at 5 ppb and decreased with higher concentrations. The total ARGs abundances in sludge increased with addition of TC or SMX, and the higher relative abundances were in the order of sul1 > tetG > sul2 > tetA > intI1 > tetS > tetC. Pearson correlation analysis showed most ARGs (tetA, tetC, tetG, tetK, tetM, sul1) were significantly correlated with intI1 (p < 0.01). - Highlights: • COD and NH{sub 4}{sup +}−N removals significantly decrease under 10 ppm TC or SMX. • Activated sludge EPS concentrations increase with increasing TC or SMX concentrations. • TC and SMX affect the microbial community diversity of activated sludge. • Actinobacteria abundances increase with increase of TC or SMX concentration. • ARGs abundance increases with addition of TC or SMX.

  19. Sequence-Based Characterization of Tn5801-Like Genomic Islands in Tetracycline-Resistant Staphylococcus pseudintermedius and Other Gram-positive Bacteria from Humans and Animals

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Hasman, Henrik; Jurado Rabadán, Sonia

    2016-01-01

    Antibiotic resistance in pathogens is often associated with mobile genetic elements, such as genomic islands (GI) including integrative and conjugative elements (ICEs). These can transfer resistance genes within and between bacteria from humans and/or animals. The aim of this study was to investi......Antibiotic resistance in pathogens is often associated with mobile genetic elements, such as genomic islands (GI) including integrative and conjugative elements (ICEs). These can transfer resistance genes within and between bacteria from humans and/or animals. The aim of this study......-like GIs appear to be relatively common in tetracycline-resistant S. pseudintermedius in Denmark. Almost identical Tn5801-like GIs were identified in different Gram-positive species of pet and human origin, suggesting that horizontal transfer of these elements has occurred between S. pseudintermedius...

  20. Healing Potentials of Oral Moringa Oleifera Leaves Extract and Tetracycline on Methicillin Resistant Staphylococcus Aureus Infected Wounds of Wistar rats.

    Science.gov (United States)

    Eyarefe, Oghenemega D; Idowu, Aderayo; Afolabi, Jeremiah M

    2015-12-20

    The effects of oral dose of aqueous extract of Moringa oleifera and tetracycline antibiotics on cutaneous wounds infected with Staphylococcus aureus were studied in eighteen adult wistar rats (159±31.5g) randomized into three groups: Group A, n = 6, Moringa oleifera-(300 mg/kg). Group B, n = 6, tetracycline (9.4 mg/kg) and Group C, n = 6, Sterile water (control). Six millimetres diameter nape wound, created on each rat under 2% xylazine (5 mg/kg) and 5% ketamine (35 mg/kg), was contaminated with Staphylococcus aureus (108 Colony Forming Unit (CFU). Following infection, treatment was commenced with daily oral dose of test preparations and the wounds were evaluated every other day i.e., day 3, 5, 7, 9, 11, 13 and 15 for wetness (wound exudation), wound edge oedema, hyperaemia, granulation tissues and contraction (diameter). Severe wound exudation existed in all the groups between days 0-3 (p = 1.00). A significantly less wound exudation was observed at days 3-5 (p = 0.000) and 5-9 (p = 0.003) (ControlMoringa). Wound edge oedema was significantly less on days 5-9 (p = 0.000) and 9-15 (p = 0.001) (ControlMoringaMoringa Moringa> Tetracycline). Differences in wound diameter was not significant except at days 5-9 (p = 0.013) (Control> Moringa >Tetracycline). Oral doses of Moringa oleifera extract (300mg/kg) and tetracycline (9.4mg/kg) are not effective as antimicrobial or immune-boosting agents to enhance healing of wounds infected with Staphylococcus aureus and hence not recommended for rapid clearance of Staphylococcus aureus infected wounds.

  1. Electrochemical aptasensor for detecting tetracycline in milk

    International Nuclear Information System (INIS)

    Le, Thi Hanh; Pham, Van Phuc; La, Thi Huyen; Le, Quang Huan; Phan, Thi Binh

    2016-01-01

    A rapid, simple and sensitive biosensor system for tetracycline detection is very important in food safety. In this paper we developed a label-free aptasensor for electrochemical detection of tetracycline. According to the electrochemical impendence spectroscopy (EIS) analysis, there was a linear relationship between the concentration of tetracycline and the electron transfer resistance from 10 to 3000 ng ml −1 of the tetracycline concentration. The detection limit was 10 ng ml −1 in 15 min detection duration. The prepared aptasensor showed a good reproducibility with an acceptable stability in tetracycline detection. The recoveries of tetracycline in spiked milk samples were in the range of 88.1%–94.2%. The aptasensor has sensitivity 98% and specificity of 100%. (paper)

  2. Autoclave treatment of pig manure does not reduce the risk of transmission and transfer of tetracycline resistance genes in soil: successive determinations with soil column experiments.

    Science.gov (United States)

    Kang, Yijun; Gu, Xian; Hao, Yangyang; Hu, Jian

    2016-03-01

    The increasing use of antibiotics, especially tetracycline, in livestock feed adversely affects animal health and ecological integrity. Therefore, approaches to decrease this risk are urgently needed. High temperatures facilitate antibiotic degradation; whether this reduces transmission risk and transfer of tetracycline-resistant bacteria (TRBs) and tetracycline resistance genes (TRGs) in soil remains unknown. Successive experiments with soil columns evaluated the effects of autoclaving pig manure (APM) on soil TRB populations and TRGs over time at different soil depths. The data showed sharp increases in TRB populations and TRGs in each subsoil layer of PM (non-APM) and APM treatments within 30 days, indicating that TRBs and TRGs transferred rapidly. The level of TRBs in the upper soil layers was approximately 15-fold higher than in subsoils. TRBs were not dependent on PM and APM levels, especially in the late phase. Nevertheless, higher levels of APM led to rapid expansion of TRBs as compared to PM. Moreover, temporal changes in TRB frequencies in total culturable bacteria (TCBs) were similar to TRBs, indicating that the impact of PM or APM on TRBs was more obvious than for TCBs. TRBs were hypothesized to depend on the numbers of TRGs and indigenous recipient bacteria. In the plough layer, five TRGs (tetB, tetG, tetM, tetW, and tetB/P) existed in each treatment within 150 days. Selective pressure of TC may not be a necessary condition for the transfer and persistence of TRGs in soil. High temperatures might reduce TRBs in PM, which had minimal impact on the transmission and transfer of TRGs in soil. Identifying alternatives to decrease TRG transmission remains a major challenge.

  3. Diversity of the tetracycline resistance gene tet(M) and identification of Tn916- and Tn5801-like (Tn6014) transposons in Staphylococcus aureus from humans and animals

    DEFF Research Database (Denmark)

    de Vries, Lisbeth Elvira; Christensen, H.; Skov, R. L.

    2009-01-01

    To analyse the sequence diversity of the tetracycline resistance gene tet(M) in Staphylococcus aureus from humans and animals and to determine mobile elements associated with tet(M) in S. aureus. In total, 205 tetracycline-resistant isolates were screened for tet(M) by PCR. tet(M) genes were...... sequenced and compared with tet(M) deposited in GenBank. Based on phylogenetic analysis isolates were screened for Tn916- and Tn5801-like xis/int genes, and transposons were confirmed by linking PCR. spa typing was performed and selected isolates were used as donors in a filter mating experiment. Forty......-one isolates (21.3%, 60.7%, 2.6% and 4.4% of the human, pig, poultry and cattle isolates, respectively) were tet(M) positive. tet(M) was located on Tn5801-like and Tn916-like transposons in humans and on a specific Tn916-like element in animals. Human isolates were of different spa types (t034, t008, t037, t...

  4. The history of the tetracyclines.

    Science.gov (United States)

    Nelson, Mark L; Levy, Stuart B

    2011-12-01

    The history of the tetracyclines involves the collective contributions of thousands of dedicated researchers, scientists, clinicians, and business executives over the course of more than 60 years. Discovered as natural products from actinomycetes soil bacteria, the tetracyclines were first reported in the scientific literature in 1948. They were noted for their broad spectrum antibacterial activity and were commercialized with clinical success beginning in the late 1940s to the early 1950s. The second-generation semisynthetic analogs and more recent third-generation compounds show the continued evolution of the tetracycline scaffold toward derivatives with increased potency as well as efficacy against tetracycline-resistant bacteria, with improved pharmacokinetic and chemical properties. Their biologic activity against a wide spectrum of microbial pathogens and their uses in mammalian models of inflammation, neurodegeneration, and other biological systems indicate that the tetracyclines will continue to be successful therapeutics in infectious diseases and as potential therapeutics against inflammation-based mammalian cell diseases. © 2011 New York Academy of Sciences.

  5. Impacts of supplementing chemical fertilizers with organic fertilizers manufactured using pig manure as a substrate on the spread of tetracycline resistance genes in soil.

    Science.gov (United States)

    Kang, Yijun; Hao, Yangyang; Shen, Min; Zhao, Qingxin; Li, Qing; Hu, Jian

    2016-08-01

    Using pig manure (PM) compost as a partial substitute for the conventional chemical fertilizers (CFs) is considered an effective approach in sustainable agricultural systems. This study aimed to analyze the impacts of supplementing CF with organic fertilizers (OFs) manufactured using pig manure as a substrate on the spread of tetracycline resistance genes (TRGs) as well as the community structures and diversities of tetracycline-resistant bacteria (TRB) in bulk and cucumber rhizosphere soils. In this study, three organic fertilizers manufactured using the PM as a substrate, namely fresh PM, common OF, and bio-organic fertilizer (BF), were supplemented with a CF. Composted manures combined with a CF did not significantly increase TRB compared with the CF alone, but PM treatment resulted in the long-term survival of TRB in soil. The use of CF+PM also increased the risk of spreading TRGs in soil. As beneficial microorganisms in BF may function as reservoirs for the spread of antibiotic resistance genes, care should be taken when adding them to the OF matrix. The PM treatment significantly altered the community structures and increased the species diversity of TRB, especially in the rhizosphere soil. BF treatment caused insignificant changes in the community structure of TRB compared with CF treatment, yet it reduced the species diversities of TRB in soil. Thus, the partial use of fresh PM as a substitute for CF could increase the risk of spread of TRGs. Apart from plant growth promotion, BF was a promising fertilizer owing to its potential ability to control TRGs. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Abundances of tetracycline, sulphonamide and beta-lactam antibiotic resistance genes in conventional wastewater treatment plants (WWTPs with different waste load.

    Directory of Open Access Journals (Sweden)

    Mailis Laht

    Full Text Available Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs, an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs were quantified using qPCR in three WWTPs of decreasing capacity located in Helsinki, Tallinn, and Tartu, respectively: sulphonamide resistance genes (sul1 and sul2, tetracycline resistance genes (tetM and tetC, and resistance genes for extended spectrum beta-lactams (blaoxa-58, blashv-34, and blactx-m-32. To avoid inconsistencies among qPCR assays we normalised the ARG abundances with 16S rRNA gene abundances while assessing if the respective genes increased or decreased during treatment. ARGs were detected in most samples; sul1, sul2, and tetM were detected in all samples. Statistically significant differences (adjusted p<0.01 between the inflow and effluent were detected in only four cases. Effluent values for blaoxa-58 and tetC decreased in the two larger plants while tetM decreased in the medium-sized plant. Only blashv-34 increased in the effluent from the medium-sized plant. In all other cases the purification process caused no significant change in the relative abundance of resistance genes, while the raw abundances fell by several orders of magnitude. Standard water quality variables (biological oxygen demand, total phosphorus and nitrogen, etc. were weakly related or unrelated to the relative abundance of resistance genes. Based on our results we conclude that there is neither considerable enrichment nor purification of antibiotic resistance genes in studied conventional WWTPs.

  7. Stochastic simulations of the tetracycline operon

    Directory of Open Access Journals (Sweden)

    Kaznessis Yiannis N

    2011-01-01

    Full Text Available Abstract Background The tetracycline operon is a self-regulated system. It is found naturally in bacteria where it confers resistance to antibiotic tetracycline. Because of the performance of the molecular elements of the tetracycline operon, these elements are widely used as parts of synthetic gene networks where the protein production can be efficiently turned on and off in response to the presence or the absence of tetracycline. In this paper, we investigate the dynamics of the tetracycline operon. To this end, we develop a mathematical model guided by experimental findings. Our model consists of biochemical reactions that capture the biomolecular interactions of this intriguing system. Having in mind that small biological systems are subjects to stochasticity, we use a stochastic algorithm to simulate the tetracycline operon behavior. A sensitivity analysis of two critical parameters embodied this system is also performed providing a useful understanding of the function of this system. Results Simulations generate a timeline of biomolecular events that confer resistance to bacteria against tetracycline. We monitor the amounts of intracellular TetR2 and TetA proteins, the two important regulatory and resistance molecules, as a function of intrecellular tetracycline. We find that lack of one of the promoters of the tetracycline operon has no influence on the total behavior of this system inferring that this promoter is not essential for Escherichia coli. Sensitivity analysis with respect to the binding strength of tetracycline to repressor and of repressor to operators suggests that these two parameters play a predominant role in the behavior of the system. The results of the simulations agree well with experimental observations such as tight repression, fast gene expression, induction with tetracycline, and small intracellular TetR2 amounts. Conclusions Computer simulations of the tetracycline operon afford augmented insight into the

  8. Stochastic simulations of the tetracycline operon

    Science.gov (United States)

    2011-01-01

    Background The tetracycline operon is a self-regulated system. It is found naturally in bacteria where it confers resistance to antibiotic tetracycline. Because of the performance of the molecular elements of the tetracycline operon, these elements are widely used as parts of synthetic gene networks where the protein production can be efficiently turned on and off in response to the presence or the absence of tetracycline. In this paper, we investigate the dynamics of the tetracycline operon. To this end, we develop a mathematical model guided by experimental findings. Our model consists of biochemical reactions that capture the biomolecular interactions of this intriguing system. Having in mind that small biological systems are subjects to stochasticity, we use a stochastic algorithm to simulate the tetracycline operon behavior. A sensitivity analysis of two critical parameters embodied this system is also performed providing a useful understanding of the function of this system. Results Simulations generate a timeline of biomolecular events that confer resistance to bacteria against tetracycline. We monitor the amounts of intracellular TetR2 and TetA proteins, the two important regulatory and resistance molecules, as a function of intrecellular tetracycline. We find that lack of one of the promoters of the tetracycline operon has no influence on the total behavior of this system inferring that this promoter is not essential for Escherichia coli. Sensitivity analysis with respect to the binding strength of tetracycline to repressor and of repressor to operators suggests that these two parameters play a predominant role in the behavior of the system. The results of the simulations agree well with experimental observations such as tight repression, fast gene expression, induction with tetracycline, and small intracellular TetR2 amounts. Conclusions Computer simulations of the tetracycline operon afford augmented insight into the interplay between its molecular

  9. Effect of temperature on the fate of genes encoding tetracycline resistance and the integrase of class 1 integrons within anaerobic and aerobic digesters treating municipal wastewater solids.

    Science.gov (United States)

    Diehl, David L; LaPara, Timothy M

    2010-12-01

    The objective of this research was to investigate the ability of anaerobic and aerobic digesters to reduce the quantity of antibiotic resistant bacteria in wastewater solids. Lab-scale digesters were operated at different temperatures (22 °C, 37 °C, 46 °C, and 55 °C) under both anaerobic and aerobic conditions and fed wastewater solids collected from a full-scale treatment facility. Quantitative PCR was used to track five genes encoding tetracycline resistance (tet(A), tet(L), tet(O), tet(W), and tet(X)) and the gene encoding the integrase (intI1) of class 1 integrons. Statistically significant reductions in the quantities of these genes occurred in the anaerobic reactors at 37 °C, 46 °C, and 55 °C, with the removal rates and removal efficiencies increasing as a function of temperature. The aerobic digesters, in contrast, were generally incapable of significantly decreasing gene quantities, although these digesters were operated at much shorter mean hydraulic residence times. This research suggests that high temperature anaerobic digestion of wastewater solids would be a suitable technology for eliminating various antibiotic resistance genes, an emerging pollutant of concern.

  10. Construction of an extended range whole-cell tetracycline biosensor by use of the tet(M) resistance gene

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

    2005-01-01

    protein gene. Tetracycline, oxytetracycline, chlortetracycline and minocycline all effectively induced the resulting Escherichia coli MC4100/pTGM biosensor and similar dose-response characteristics were recorded by flow cytometry for all four compounds. The novel tetracycline biosensor was responsive...

  11. Effect of red mud addition on tetracycline and copper resistance genes and microbial community during the full scale swine manure composting.

    Science.gov (United States)

    Wang, Rui; Zhang, Junya; Sui, Qianwen; Wan, Hefeng; Tong, Juan; Chen, Meixue; Wei, Yuansong; Wei, Dongbin

    2016-09-01

    Swine manure has been considered as the reservoir of antibiotic resistance genes (ARGs). Composting is one of the most suitable technologies for treating livestock manures, and red mud was proved to have a positive effect on nitrogen conservation during composting. This study investigated the abundance of eight tetracycline and three copper resistance genes, the bacterial community during the full scale swine manure composting with or without addition of red mud. The results showed that ARGs in swine manure could be effectively removed through composting (reduced by 2.4log copies/g TS), especially during the thermophilic phase (reduced by 1.5log copies/g TS), which the main contributor might be temperature. Additionally, evolution of bacterial community could also have a great influence on ARGs. Although addition of red mud could enhance nitrogen conservation, it obviously hindered removal of ARGs (reduced by 1.7log copies/g TS) and affected shaping of bacterial community during composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Effects of oxytetracycline on archaeal community, and tetracycline resistance genes in anaerobic co-digestion of pig manure and wheat straw.

    Science.gov (United States)

    Wang, Xiaojuan; Pan, Hongjia; Gu, Jie; Qian, Xun; Gao, Hua; Qin, Qingjun

    2016-12-01

    In this study, the effects of different concentrations of oxytetracycline (OTC) on biogas production, archaeal community structure, and the levels of tetracycline resistance genes (TRGs) were investigated in the anaerobic co-digestion products of pig manure and wheat straw. PCR denaturing gradient gel electrophoresis analysis and real-time quantitative polymerase chain reaction (RT-qPCR) (PCR) were used to detect the archaeal community structure and the levels of four TRGs: tet(M), tet(Q), tet(W), and tet(C). The results showed that anaerobic co-digestion with OTC at concentrations of 60, 100, and 140 mg/kg (dry weight of pig manure) reduced the cumulative biogas production levels by 9.9%, 10.4%, and 14.1%, respectively, compared with that produced by the control, which lacked the antibiotic. The addition of OTC substantially modified the structure of the archaeal community. Two orders were identified by phylogenetic analysis, that is, Pseudomonadales and Methanomicrobiales, and the methanogen present during anaerobic co-digestion with OTC may have been resistant to OTC. The abundances of tet(Q) and tet(W) genes increased as the OTC concentration increased, whereas the abundances of tet(M) and tet(C) genes decreased as the OTC concentration increased.

  13. Draft Genome Sequence of Neisseria gonorrhoeae Strain NG_869 with Penicillin, Tetracycline and Ciprofloxacin Resistance Determinants Isolated from Malaysia

    OpenAIRE

    Ang, Geik Yong; Yu, Choo Yee; Yong, Delicia Ann; Cheong, Yuet Meng; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Gonorrhea is a sexually transmitted infection caused by Neisseria gonorrhoeae and the increasing reports of multidrug-resistant gonococcal isolates are a global public health care concern. Herein, we report the genome sequence of N. gonorrhoeae strain NG_869 isolated from Malaysia which may provide insights into the drug resistance determinants in gonococcal bacteria.

  14. Identification of DHA-23, a Novel Plasmid-mediated and Inducible AmpC beta-Lactamase from Enterobacteriaceae in Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Shyang eHsieh

    2015-05-01

    Full Text Available Objectives: AmpC β-lactamases are classified as Amber Class C and Bush Group 1. AmpC β-lactamases can hydrolyze broad and extended-spectrum cephalosporins, and are not inhibited by β-lactamase inhibitors such as clavulanic acid. This study was conducted to identify DHA-23, a novel plasmid-mediated and inducible AmpC β-lactamase obtained from Enterobacteriaceae. Methods: A total of 210 carbapenem-resistant Enterobacteriaceae isolates were collected from a medical center (comprising 2 branches in Northern Taiwan during 2009–2012. AmpC β-lactamase genes were analyzed through a polymerase chain reaction using plasmid DNA templates and gene sequencing. The genetic relationships of the isolates were typed using pulsed-field gel electrophoresis following the digestion of intact genomic DNA by using XbaI. Results: Three enterobacterial isolates (one Escherichia coli and 2 Klebsiella pneumoniae were obtained from 3 hospitalized patients. All 3 isolates were resistant or intermediately susceptible to all β-lactams, and exhibited reduced susceptibility to carbapenems. These 3 isolates expressed a novel AmpC β-lactamase, designated DHA-23, approved by the curators of the Lahey website. DHA-23 differs from DHA-1 and DHA-6 by one amino acid substitution (Ser245Ala, exhibiting 2 amino acid changes compared with DHA-7 and DHA-Morganella morganii; 3 amino acid changes compared with DHA-3; 4 amino acid changes compared with DHA-5; and 8 amino acid changes compared with DHA-2 (> 97% identity. This AmpC β-lactamase is inducible using a system involving ampR. Conclusion: This is the first report to address DHA-23, a novel AmpC β-lactamase. DHA-type β-lactamases are continuous threat in Taiwan.

  15. High dietary zinc supplementation increases the occurrence of tetracycline and sulfonamide resistance genes in the intestine of weaned pigs

    OpenAIRE

    Vahjen, Wilfried; Pietruszy?ska, Dominika; Starke, Ingo C.; Zentek, J?rgen

    2015-01-01

    Background Dietary zinc oxide is used in pig nutrition to combat post weaning diarrhoea. Recent data suggests that high doses (2.5?g/kg feed) increase the bacterial antibiotic resistance development in weaned pigs. Therefore, the aim of this study was to investigate the development of enterobacterial antibiotic resistance genes in the intestinal tract of weaned pigs. Findings Weaned pigs were fed diets for 4?weeks containing 57 (low), 164 (intermediate) or 2425 (high) mg?kg?1 analytical grade...

  16. High prevalence of plasmid-mediated 16S rRNA methylase gene rmtB among Escherichia coli clinical isolates from a Chinese teaching hospital

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    Zhang Xue-qing

    2010-06-01

    transposon, Tn3, was located upstream of the rmtB. Nineteen clonal patterns were obtained by PFGE, with type H representing the prevailing pattern. Conclusion A high prevalence of plasmid-mediated rmtB gene was found among clinical E. coli isolates from a Chinese teaching hospital. Both horizontal gene transfer and clonal spread were responsible for the dissemination of the rmtB gene.

  17. Prevalence and Antibiotic Resistance against Tetracycline in Campylobacter jejuni and C. coli in Cattle and Beef Meat from Selangor, Malaysia

    OpenAIRE

    Premarathne, Jayasekara M. K. J. K.; Anuar, Aimi S.; Thung, Tze Young; Satharasinghe, Dilan A.; Jambari, Nuzul Noorahya; Abdul-Mutalib, Noor-Azira; Huat, John Tang Yew; Basri, Dayang F.; Rukayadi, Yaya; Nakaguchi, Yoshitsugu; Nishibuchi, Mitsuaki; Radu, Son

    2017-01-01

    Campylobacter is a major foodborne pathogen frequently associated with human bacterial gastroenteritis in the world. This study was conducted to determine the prevalence and antibiotic resistance of Campylobacter spp. in the beef food system in Malaysia. A total of 340 samples consisting of cattle feces (n = 100), beef (n = 120) from wet markets and beef (n = 120) from hypermarkets were analyzed for Campylobacter spp. The overall prevalence of Campylobacter was 17.4%, consisting of 33% in cat...

  18. Role of the RS1 sequence of the cholera vibrio in amplification of the segment of plasmid DNA carrying the gene of resistance to tetracycline and the genes of cholera toxin

    International Nuclear Information System (INIS)

    Fil'kova, S.L.; Il'ina, T.S.; Gintsburg, A.L.; Yanishevskii, N.V.; Smirnov, G.B.

    1988-01-01

    The hybrid plasmid pCO107, representing cointegrate 14(2)-5(2) of two plasmids, an F-derivative (pOX38) and a PBR322-derivative (pCT105) with an RS1 sequence of the cholera vibrio cloned in its makeup, contains two copes of RS1 at the sites of union of the two plasmids. Using a tetracycline resistance marker (Tc R ) of the plasmid pCT105, clones were isolated which have an elevated level of resistance to tetracycline (an increase of from 4- to 30-fold). Using restriction analysis and the Southern blot method of hybridization it was shown that the increase in the level of resistance of tetracycline is associated with the amplification of pCT105 portion of the cointegrate, and that the process of amplification is governed by the presence of direct repeats of the RS1 sequence at its ends. The increase in the number of copies of the pCT105 segment, which contains in its composition the genes of cholera toxin (vct), is accompanied by an increase in toxin production

  19. Radiation deamination of tetracycline

    International Nuclear Information System (INIS)

    Kuduk-Jaworska, J.

    1980-01-01

    The fundamental product of tetracycline hydrochlorine gamma radiolysis was separated in its solid state. From the results of spectroscopic studies it has been established that it is des-N,N-dimethylaminotetracycline. (author)

  20. Distribution and characterization of ampicillin- and tetracycline-resistant Escherichia coli from feedlot cattle fed subtherapeutic antimicrobials

    Directory of Open Access Journals (Sweden)

    Yanke L Jay

    2011-04-01

    Full Text Available Abstract Background Feedlot cattle in North America are routinely fed subtherapeutic levels of antimicrobials to prevent disease and improve the efficiency of growth. This practice has been shown to promote antimicrobial resistance (AMR in subpopulations of intestinal microflora including Escherichia coli. To date, studies of AMR in feedlot production settings have rarely employed selective isolation, therefore yielding too few AMR isolates to enable characterization of the emergence and nature of AMR in E. coli as an indicator bacterium. E. coli isolates (n = 531 were recovered from 140 cattle that were housed (10 animals/pen in 14 pens and received no dietary antimicrobials (control - 5 pens, CON, or were intermittently administered subtherapeutic levels of chlortetracycline (5 pens-T, chlortetracycline + sulfamethazine (4 pens-TS, or virginiamycin (5 pens-V for two separate periods over a 9-month feeding period. Phenotype and genotype of the isolates were determined by susceptibility testing and pulsed field gel electrophoresis and distribution of characterized isolates among housed cattle reported. It was hypothesized that the feeding of subtherapeutic antibiotics would increase the isolation of distinct genotypes of AMR E. coli from cattle. Results Overall, patterns of antimicrobial resistance expressed by E. coli isolates did not change among diet groups (CON vs. antibiotic treatments, however; isolates obtained on selective plates (i.e., MA,MT, exhibited multi-resistance to sulfamethoxazole and chloramphenicol more frequently when obtained from TS-fed steers than from other treatments. Antibiograms and PFGE patterns suggested that AMR E. coli were readily transferred among steers within pens. Most MT isolates possessed the tet(B efflux gene (58.2, 53.5, 40.8, and 50.6% of isolates from CON, T, TS, and V steers, respectively whereas among the MA (ampicillin-resistant isolates, the tem1-like determinant was predominant (occurring in 50, 66

  1. Tannic acid affects the phenotype of Staphylococcus aureus resistant to tetracycline and erythromycin by inhibition of efflux pumps.

    Science.gov (United States)

    Tintino, Saulo R; Morais-Tintino, Cícera D; Campina, Fábia F; Costa, Maria do S; Menezes, Irwin R A; de Matos, Yedda Maria L S; Calixto-Júnior, João T; Pereira, Pedro S; Siqueira-Junior, José P; Leal-Balbino, Teresa C; Coutinho, Henrique D M; Balbino, Valdir Q

    2017-10-01

    The widespread use of antibiotics created selective pressure for the emergence of strains that would persist despite antibiotic toxicity. The bacterial resistance mechanisms are several, with efflux pumps being one of the main ones. These pumps are membrane proteins with the function of removing antibiotics from the cell cytoplasm. Due to this importance, the aim of this work was to evaluate the inhibitory effect of tannic acid against efflux pumps expressed by the Staphylococcus aureus RN4220 and IS-58 strains. The efflux pump inhibition was assayed using a sub-inhibitory concentration of efflux pump standard inhibitors and tannic acid (MIC/8), observing their capacity to decrease the MIC of Ethidium bromide (EtBr) and antibiotics due the possible inhibitory effect of these substances. The MICs of EtBr and antibiotics were significantly different in the presence of tannic acid, indicating the inhibitory effect of this product against efflux pumps of both strains. These results indicate the possible usage of tannic acid asan inhibitor and an adjuvant in the antibiotic therapy against multidrug resistant bacteria (MDR). Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Effects of chlortetracycline and copper on tetracyclines and copper resistance genes and microbial community during swine manure anaerobic digestion.

    Science.gov (United States)

    Wang, Rui; Chen, Meixue; Feng, Feng; Zhang, Junya; Sui, Qianwen; Tong, Juan; Wei, Yuansong; Wei, Dongbin

    2017-08-01

    As antibiotic and heavy metals are over used in the livestock industry, animal manure is a reservoir of antibiotic resistance genes (ARGs). Anaerobic digestion has been reported to have the potential to reduce ARGs. However, few studies investigated whether reduction of ARGs would be affected by different external pressures including antibiotics and heavy metals during anaerobic digestion. The purpose of this study was thus to investigate effects of both chlortetracycline (CTC) and Cu on reduction of ARGs, heavy metal resistance genes (HMRGs) and mobile genetic elements (MGEs) during the swine manure anaerobic digestion. The results showed that the predominant ARGs (tetO, tetW, tetX, tetL) could be effectively reduced (approximately 1.00 log copies/g TS) through mesophilic anaerobic digestion. Microbial community evolution was the main driver. It was interesting that Treponema might indicate the termination of anaerobic digestion and compete with ARGs host bacteria. Addition of CTC, Cu and CTC+Cu affected microbial community change and hindered removal of ARGs, especially, CTC+Cu seriously affected Treponema and ARGs during anaerobic digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Antibiotic resistance in Escherichia coli in husbandry animals: the African perspective.

    Science.gov (United States)

    Alonso, C A; Zarazaga, M; Ben Sallem, R; Jouini, A; Ben Slama, K; Torres, C

    2017-05-01

    In the last few years, different surveillances have been published in Africa, especially in northern countries, regarding antimicrobial resistance among husbandry animals. Information is still scarce, but the available data show a worrying picture. Although the highest resistance rates have been described against tetracycline, penicillins and sulphonamides, prevalence of plasmid-mediated quinolone resistance genes and extended spectrum β-lactamase (ESBL) are being increasingly reported. Among ESBLs, the CTX-M-1 group was dominant in most African surveys. Within this group, CTX-M-15 was the main variant both in animals and humans, except in Tunisia where CTX-M-1 was more frequently detected among Escherichia coli from poultry. Certain bla CTX -M-15 -harbouring clones (ST131/B2 or ST405/D) are mainly identified in humans, but they have also been reported in livestock species from Tanzania, Nigeria or Tunisia. Moreover, several reports suggest an inter-host circulation of specific plasmids (e.g. bla CTX -M-1 -carrying IncI1/ST3 in Tunisia, IncY- and Inc-untypeable replicons co-harbouring qnrS1 and bla CTX -M-15 in Tanzania and the worldwide distributed bla CTX -M-15 -carrying IncF-type plasmids). International trade of poultry meat seems to have contributed to the spread of other ESBL variants, such as CTX-M-14, and clones. Furthermore, first descriptions of OXA-48- and OXA-181-producing E. coli have been recently documented in cattle from Egypt, and the emergent plasmid-mediated colistin resistance mcr-1 gene has been also identified in chickens from Algeria, Tunisia and South Africa. These data reflect the urgent need of a larger regulation in the use of veterinary drugs and the implementation of surveillance programmes in order to decelerate the advance of antimicrobial resistance in this continent. © 2017 The Society for Applied Microbiology.

  4. Incidence, distribution, and spread of tetracycline resistance determinants and integron-associated antibiotic resistance genes among motile aeromonads from a fish farming environment

    DEFF Research Database (Denmark)

    Schmidt, Anja S.; Bruun, Morten Sichlau; Dalsgaard, Inger

    2001-01-01

    . Microbiol. 66:4908-4915, 2000), the predominant resistance phenotype (37%) being a combined oxytetracycline (OTC) and sulphadiazine/trimethoprim resistance. Combined sulphonamide/trimethoprim resistance (135 isolates) appeared closely related to the presence of a class 1 integron (141 strains). Among...

  5. Antimicrobial resistance in commensal Escherichia coli isolated from animals at slaughter

    Science.gov (United States)

    Wasyl, Dariusz; Hoszowski, Andrzej; Zając, Magdalena; Szulowski, Krzysztof

    2013-01-01

    Monitoring of antimicrobial resistance in commensal Escherichia coli (N = 3430) isolated from slaughtered broilers, laying hens, turkeys, swine, and cattle in Poland has been run between 2009 and 2012. Based on minimal inhibitory concentration (MIC) microbiological resistance to each of 14 tested antimicrobials was found reaching the highest values for tetracycline (43.3%), ampicillin (42.3%), and ciprofloxacin (39.0%) whereas the lowest for colistin (0.9%), cephalosporins (3.6 ÷ 3.8%), and florfenicol (3.8%). The highest prevalence of resistance was noted in broiler and turkey isolates, whereas it was rare in cattle. That finding along with resistance patterns specific to isolation source might reflect antimicrobial consumption, usage preferences or management practices in specific animals. Regression analysis has identified changes in prevalence of microbiological resistance and shifts of MIC values. Critically important fluoroquinolone resistance was worrisome in poultry isolates, but did not change over the study period. The difference (4.7%) between resistance to ciprofloxacin and nalidixic acid indicated the scale of plasmid-mediated quinolone resistance. Cephalosporin resistance were found in less than 3.8% of the isolates but an increasing trends were observed in poultry and MIC shift in the ones from cattle. Gentamycin resistance was also increasing in E. coli of turkey and cattle origin although prevalence of streptomycin resistance in laying hens decreased considerably. Simultaneously, decreasing MIC for phenicols observed in cattle and layers isolates as well as tetracycline values in E. coli from laying hens prove that antimicrobial resistance is multivariable phenomenon not only directly related to antimicrobial usage. Further studies should elucidate the scope of commensal E. coli as reservoirs of resistance genes, their spread and possible threats for human and animal health. PMID:23935596

  6. Antimicrobial resistance in commensal Escherichia coli isolated from animals at slaughter

    Directory of Open Access Journals (Sweden)

    Dariusz eWasyl

    2013-08-01

    Full Text Available Monitoring of antimicrobial resistance in commensal Escherichia coli (N = 3430 isolated from slaughtered broilers, laying hens, turkeys, swine, and cattle in Poland has been run between 2009 and 2012. Based on minimal inhibitory concentration (MIC microbiological resistance to each of 14 tested antimicrobials was found reaching the highest values for tetracycline (43.3%, ampicillin (42.3%, and ciprofloxacin (39.0% whereas the lowest for colistin (0.9%, cephalosporins (3.6 ÷ 3.8%, and florfenicol (3.8%. The highest prevalence of resistance was noted in broiler and turkey isolates, whereas it was rare in cattle. That finding along with resistance patterns specific to isolation source might reflect antimicrobial consumption, usage preferences or management practices in specific animals. Regression analysis has identified changes in prevalence of microbiological resistance and shifts of MIC values. Critically important fluoroquinolone resistance was worrisome in poultry isolates, but did not change over the study period. The difference (4.7% between resistance to ciprofloxacin and nalidixic acid indicated the scale of plasmid-mediated quinolone resistance. Cephalosporin resistance were found in less than 3.8% of the isolates but an increasing trends were observed in poultry and MIC shift in the ones from cattle. Gentamycin resistance was also increasing in E. coli of turkey and cattle origin although prevalence of streptomycin resistance in laying hens decreased considerably. Simultaneously, decreasing MIC for phenicols observed in cattle and layers isolates as well as tetracycline values in E. coli from laying hens prove that antimicrobial resistance is multivariable phenomenon not only directly related to antimicrobial usage. Further studies should elucidate the scope of commensal E. coli as reservoirs of resistance genes, their spread and possible threats for human and animal health.

  7. Tetracycline and oxytetracycline resistance determinants detected in Bacillus cereus strains isolated from honey samples Detección de determinantes de resistencia a tetraciclina y oxitetraciclina en cepas de Bacillus cereus aisladas de muestras de miel

    Directory of Open Access Journals (Sweden)

    A. C. López

    2008-12-01

    Full Text Available The aim of this study was to investigate the presence of tetracycline and oxytetracycline resistance determinants in Bacillus cereus strains isolated from honey samples. Of a total of 77 isolates analyzed, 30 (39% exhibited resistance to tetracyclines according to the results of a disk diffusion method. Resistant strains (n=30 were screened by PCR for the presence of the resistant determinants tetK, tetL, tetM, tetO, tetW, otrA and otrB and their MIC values for tetracycline, oxytetracycline and minocycline were assessed. According to the PCR results, 23 isolates (77% presented at least one tetracycline or oxytetracycline resistance determinant. The tetK genotype was present in 10 isolates while the tetL, tetM, and otrA genotypes were present in 3, 2, and 5 isolates, respectively. In addition, 2 isolates of the tetK plus tetM genotype, 1 of the tetK plus tetL genotype, and 1 of the tetK plus otrA genotype were found. All isolates were tetW, tetO and otrB negatives. On the other hand, 7 isolates (23% showed a tetracycline-resistant and/or minocyclineresistant phenotype (MIC but did not carry any of the tet or otr determinants investigated in this study. This research has shown that B. cereus isolates from honey samples contain a variety of tetracycline and oxytetracycline resistance genes, including the tetK and tetL determinants which encode for efflux proteins, and tetM and otrA, which encode for ribosomal protection proteins. These findings indicate that strains isolated from honeys could represent a reservoir for tetracycline resistance genes. To our knowledge, this is the first report of tetracycline-resistant and oxytetracyclineresistant B. cereus strains carrying the tetK determinant, and also the first report of oxytetracycline-resistant and tetracycline- resistant Bacillus species carrying the otrA determinant.El objetivo del presente estudio ha sido investigar la presencia de diversos determinantes de resistencia a tetraciclina y

  8. Prevalence of Chlamydia trachomatis, Ureaplasma spp., Mycoplasma genitalium and Mycoplasma hominis among outpatients in central Greece: absence of tetracycline resistance gene tet(M over a 4-year period study

    Directory of Open Access Journals (Sweden)

    A. Ikonomidis

    2016-01-01

    Full Text Available A total of 301 men and women attending local urologists and gynaecologists in the state of Thessaly, central Greece, were tested for Chlamydia trachomatis, Ureaplasma spp., Mycoplasma genitalium and Mycoplasma hominis DNA. Investigation of the tet(M gene, which confers tetracycline resistance in these genera, was also performed. Low incidence of C. trachomatis and Mycoplasma spp. as well as high prevalence of Ureaplasma spp., especially among women, were found. The tet(M gene was absent in all cases, notably in a region where doxycycline administration remains the first therapeutic option unless special medical conditions direct otherwise.

  9. The effect of the administration of three different antimicrobial premix formulations via the liquid feeding system on the occurrence of Enterobacteriaceae resistant to tetracycline in the liquid feed for pigs.

    Science.gov (United States)

    Heller, O; Sidler, X; Hässig, M; Thanner, S; Bee, G; Gutzwiller, A; Stephan, R

    2016-06-01

    The oral group treatment is still a common procedure in swine production. This project studied the effect of the application of 3 different formulations of antimicrobial premixes (1. chlortetracycline, 2. chlortetracycline + sulfadimidine + tylosin, 3. sulfadimidine + sulfathiazole + trimethoprim) via the liquid feeding system on the occurrence of tetracycline-resistant Enterobacteriaceae (Ent-Tetr) in the liquid feed. 156 and 112 feed samples were collected between April and December 2015 in 13 case and 14 control farms, respectively. The 27 farms were randomly selected pig fattening farms located in different parts of Switzerland. The number of feed samples that contained Ent-Tetr as well as the number of Enterobacteriaceae resistant to tetracycline per sample was significantly higher in the case group than in the control group. The use of any of the 3 antimicrobial combinations turned out to be the main risk factor for the occurrence of Ent-Tetr in the liquid feed. Our results suggest that liquid feed containing antimicrobials is a reservoir of antimicrobial resistant bacteria in swine production.

  10. ß-lactamasas AmpC plasmídicas tipo CMY-2 emergentes en Tucumán, Argentina CMY-2-type plasmid-mediated AmpC ß-Lactamases emerging in Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    María A. Jure

    2011-03-01

    Full Text Available En los últimos años, algunas enterobacterias como Klebsiella pneumoniae, Proteus mirabilis y Escherichia coli adquirieron resistencia a las cefalosporinas de tercera generación (C3G por la adquisición de ß-lactamasas de tipo AmpC plasmídicas, mecanismo que se está comunicando cada vez con mayor frecuencia en el mundo. El objetivo de esta investigación fue detectar la emergencia de ß-lactamasas AmpC plasmídicas en Tucumán e identificar sus tipos predominantes. Se estudió la sensibilidad a diferentes antimicrobianos de 733 aislamientos clínicos consecutivos de enterobacterias obtenidos en el período marzo-julio de 2009 en tres centros asistenciales de nuestra provincia. Se realizaron pruebas de sensibilidad por difusión y se seleccionaron tres aislamientos de E. coli y uno de P. mirabilis resistentes a C3G y a cefoxitina. En estos aislamientos se determinó la CIM por E-test y se evaluó el mecanismo enzimático de resistencia mediante sinergia con discos de ácido aminofenilborónico y ensayo microbiológico de Masuda. Se realizó PCR usando cebadores dirigidos al grupo CIT de las AmpC plasmídicas. Se obtuvo un amplicón de 462 pb que fue secuenciado; presentó un 100% de identidad con blaCMY-2 en los cuatro aislamientos. En conclusión, las ß-lactamasas AmpC tipo CMY-2 emergieron en nuestro medio, de modo que es importante implementar una vigilancia sistemática de estas resistencias para evitar potenciales consecuencias clínicas y epidemiológicas.In the last years, Enterobacteriaceae such as Klebsiella pneumoniae, Proteus mirabilis and Escherichia coli, have acquired resistance to third-generation cephalosporins (C3G because of the presence of plasmid-mediated AmpC ß-lactamases. The aim of this work was to detect plasmid AmpC enzymes and to investigate the predominant types in our region. Between March and July 2009, 733 consecutive isolates of Enterobacteriaceae derived from hospitals and outpatient centers were studied

  11. Antibiotic resistance plasmids of Staphylococcus aureus and their clinical importance

    International Nuclear Information System (INIS)

    Lacey, R.W.

    1975-01-01

    A variety of plasmids were isolated physically, and most antibiotic resistance is thought to be plasmid mediated. A number of characters (e.g., resistance to erythromycin or methicillin, and production of pigment) are determined by genes that do not give clear indications of either plasmid or chromosomal location. Although the formation of a particular plasmid is probably, even in bacterial terms, a very rare event, once formed such an element can spread rapidly among the bacterial population. The spectacular increase in the incidence of penicillinase-producing hospital strains in the late 1940's could have been due in part to this process. Evidence is stronger, however, for the intercell transfer of recently isolated plasmids coding for resistance to fusidic acid (and penicillinase production), or for neomycin, or for tetracycline resistance. Study of bacterial plasmids can resolve fundamental biochemical problems, and give some insight into the life of the cell at the molecular level. But the immediate application of the study of staphylococcal plasmids may be directed towards improving the effectiveness of antibiotic therapy. The most important aspect of future anti-staphylococcal chemotherapy should thus be the limitation of the use of antibiotics, particularly for application to the skin and nose. (U.S.)

  12. Molecular characterization of extended-spectrum β-lactamase, plasmid-mediated AmpC cephalosporinase and carbapenemase genes among Enterobacteriaceae isolates in five medical centres of East and West Azerbaijan, Iran.

    Science.gov (United States)

    Sadeghi, Mohammad Reza; Ghotaslou, Reza; Akhi, Mohammad Taghi; Asgharzadeh, Mohammad; Hasani, Alka

    2016-11-01

    Very little is known about the occurrence and various types of extended-spectrum β-lactamase (ESBL), AmpC and carbapenemase in Iran. The aims of this study were to determine the prevalence of ESBLs, AmpCs and carbapenemase genes among Enterobacteriaceae in Azerbaijan and to characterize the genetic composition of the detected genes. A total of 307 Enterobacteriaceae isolates, recovered from five medical centres, were screened for ESBL, AmpC and carbapenemase activities by the disc diffusion method and phenotypic confirmatory tests. The 162 selected strains (third-generation cephalosporins, cefoxitin- or carbapenem-resistant strains with positive or negative phenotypic confirmatory tests) were selected for multiplex PCR screening for β-lactamase genes, and detected genes were confirmed by sequencing. Of 162 isolates, 156 harboured 1 to 6 β-lactamase genes of 41 types. The most prevalent genes were blaTEM-1 (29.9 %), followed by blaCTX-M-15 (25.7 %). Plasmid-mediated AmpC was detected in 66 strains (21.5 %) alone or in combination with other genes. Carbapenemase-encoding genes were detected in 18 strains (5.8 %) of 27 carbapenem-non-susceptible isolates including 11, 7, 3 and 1 cases of blaOXA-48, blaNDM-1, blaKPC-2 and blaKPC-3 genes, respectively. Interestingly, 148 (94.8 %) of 156 strains with any β-lactamase gene were found to have a multidrug-resistant pattern. The rate of resistance to β-lactams and multidrug-resistant Enterobacteriaceae is high in Azerbaijan. All positive strains for carbapenemase genes were resistant to all β-lactams. The present study reveals the high occurrence of CTX-M-type ESBLs followed by TEM and SHV variants among Enterobacteriaceae isolates. East Azerbaijan seems to be an alarming focus for OXA-48, NDM-1 and KPC dissemination.

  13. In vitro activities and detection performances of cefmetazole and flomoxef for extended-spectrum β-lactamase and plasmid-mediated AmpC β-lactamase-producing Enterobacteriaceae.

    Science.gov (United States)

    Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

    2016-04-01

    To investigate the in vitro activities of cephamycins (cefmetazole and flomoxef) for extended-spectrum β-lactamase (ESBL)- and plasmid-mediated AmpC β-lactamase (pAmpC)-producing Enterobacteriaceae, a total of 574 third-generation cephalosporin-resistant clinical isolates were collected at a Japanese multicenter study. PCR and sequencing identified 394 isolates with only ESBL genes, 63 isolates with only pAmpC genes, and 6 isolates with both ESBL and pAmpC genes. blaCTX-M types predominated 95.5% of the ESBL genes, and blaCMY-2 predominated 91.3% of the pAmpC genes. The MIC50/90 values of cefmetazole and flomoxef were ≤ 1/4 and ≤ 1/≤ 1 μg/mL for isolates with only ESBL genes, respectively, and 16/>16 and 8/16 μg/mL for isolates with only pAmpC genes, respectively. Flomoxef ≥ 4 μg/mL had the best screening performance for the detection of isolates with pAmpC genes. Flomoxef had better in vitro activities against ESBL-producing Enterobacteriaceae and provided a clearer distinction between ESBL and pAmpC-producing Enterobacteriaceae compared to cefmetazole. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. In vitro transfer of multiple resistance observed in vivo during a Salmonella london epidemic.

    Science.gov (United States)

    Lantos, J; Marjai, E

    1980-01-01

    Between 1976 and 1978, waves of Salmonella london infections conveyed by raw meat and meat products were observed. The strains isolated during the epidemic were first susceptible then developed multiple antibiotic resistance. The identical antibiotic resistance patterns of the strain and their more frequent occurrence in hospital environments indicated plasmid-mediated resistance. R-plasmid transfer, minimum inhibition concentration and resistance elimination were studied in representative strains. The resistant S. london strain and transconjugants of Escherichia coli rendered resistant were compared. The results proved that multiple resistance was plasmid-mediated.

  15. Antimicrobial resistance genes in marine bacteria and human uropathogenic Escherichia coli from a region of intensive aquaculture.

    Science.gov (United States)

    Tomova, Alexandra; Ivanova, Larisa; Buschmann, Alejandro H; Rioseco, Maria Luisa; Kalsi, Rajinder K; Godfrey, Henry P; Cabello, Felipe C

    2015-10-01

    Antimicrobials are heavily used in Chilean salmon aquaculture. We previously found significant differences in antimicrobial-resistant bacteria between sediments from an aquaculture and a non-aquaculture site. We now show that levels of antimicrobial resistance genes (ARG) are significantly higher in antimicrobial-selected marine bacteria than in unselected bacteria from these sites. While ARG in tetracycline- and florfenicol-selected bacteria from aquaculture and non-aquaculture sites were equally frequent, there were significantly more plasmid-mediated quinolone resistance genes per bacterium and significantly higher numbers of qnrB genes in quinolone-selected bacteria from the aquaculture site. Quinolone-resistant urinary Escherichia coli from patients in the Chilean aquacultural region were significantly enriched for qnrB (including a novel qnrB gene), qnrS, qnrA and aac(6')-1b, compared with isolates from New York City. Sequences of qnrA1, qnrB1 and qnrS1 in quinolone-resistant Chilean E. coli and Chilean marine bacteria were identical, suggesting horizontal gene transfer between antimicrobial-resistant marine bacteria and human pathogens. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. The effect of production type and antimicrobial usage on the occurrence of tetracycline resistant E. coli in danish slaughter pig farms

    DEFF Research Database (Denmark)

    Struve, Tina; Vigre, Håkan; Wingstrand, Anne

    The Qualysafe project was initiated in 2007 to support and strengthen the sustainable production systems in Danish food production. One of the objectives of the epidemiological investigation was to find new methods to improve food safety in conventional as well as in alternative pig production...... systems. At nine different slaughterhouses 1500 ceacum samples were collected from slaughter pigs originating from 226 farms. One thousand samples were analyzed and one E. coli isolate per sample was susceptibility tested to Tetracycline. Data on management practice and health status at farm level...... the farm types, with the Organic having the lowest consumption (0.14 doses /annually produced slaughter pig) while Free Range had the highest consumption (0,85 doses/annually produced slaughter pig) and Conventional farms was in between (0.67 doses/annually produced slaughter pig). The effect...

  17. Shigella Antimicrobial Drug Resistance Mechanisms, 2004-2014.

    Science.gov (United States)

    Nüesch-Inderbinen, Magdalena; Heini, Nicole; Zurfluh, Katrin; Althaus, Denise; Hächler, Herbert; Stephan, Roger

    2016-06-01

    To determine antimicrobial drug resistance mechanisms of Shigella spp., we analyzed 344 isolates collected in Switzerland during 2004-2014. Overall, 78.5% of isolates were multidrug resistant; 10.5% were ciprofloxacin resistant; and 2% harbored mph(A), a plasmid-mediated gene that confers reduced susceptibility to azithromycin, a last-resort antimicrobial agent for shigellosis.

  18. The role of zero valent iron on the fate of tetracycline resistance genes and class 1 integrons during thermophilic anaerobic co-digestion of waste sludge and kitchen waste.

    Science.gov (United States)

    Gao, Pin; Gu, Chaochao; Wei, Xin; Li, Xiang; Chen, Hong; Jia, Hanzhong; Liu, Zhenhong; Xue, Gang; Ma, Chunyan

    2017-03-15

    Activated sludge has been identified as a potential significant source of antibiotic resistance genes (ARGs) to the environment. Anaerobic digestion is extensively used for sludge stabilization and resource recovery, and represents a crucial process for controlling the dissemination of ARGs prior to land application of digested sludge. The objective of this study is to investigate the effect of zero valent iron (Fe 0 ) on the attenuation of seven representative tetracycline resistance genes (tet, tet(A), tet(C), tet(G), tet(M), tet(O), tet(W), and tet(X)), and the integrase gene intI1 during thermophilic anaerobic co-digestion of waste sludge and kitchen waste. Significant decrease (P  0.05) were found for all gene targets between digesters with Fe 0 dosages of 5 and 60 g/L. A first-order kinetic model favorably described the trends in concentrations of tet and intI1 gene targets during thermophilic anaerobic digestion with or without Fe 0 . Notably, tet genes encoding different resistance mechanisms behaved distinctly in anaerobic digesters, although addition of Fe 0 could enhance their reduction. The overall results of this research suggest that thermophilic anaerobic digestion with Fe 0 can be a potential alternative technology for the attenuation of tet and intI1 genes in waste sludge. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Antibiotic Resistance of Salmonella enterica Serovar Typhi in Kolkata, India, and In Vitro Experiments on Effect of Combined Chemotherapy

    Directory of Open Access Journals (Sweden)

    Shyamapada Mandal

    2012-01-01

    Full Text Available This communication states the changing patterns of Salmonella enterica serovar Typhi (S. Typhi isolates causing enteric fever in and around Kolkata, India. Among the isolates resistance to ampicillin (A, chloramphenicol (C, cotrimoxazole (Co and tetracycline (T were plasmid mediated; the plasmid was unstable in S. Typhi, and the other enteric bacteria like Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were found to be the potential source of dissemination of such plasmids into S. Typhi. The infection with such S. Typhi strains were successfully treated with ciprofloxacin (Cp: MICs 0.0075–0.075 μg mL−1 and/or ofloxacin (Ofx: MICs 0.0125–0.075 μg mL−1, but in the later course, the S. Typhi strains, showing resistance to nalidixic acid, developed low level of resistance to Cp and Ofx, causing the treatment failure. Thus, the treatment regimen was shifted to the third generation cephalosporins like ceftriaxone (Ct and cefotaxime (Cf. Keeping in mind the anticipation of development of resistance to Ct/Cf, we prepared the treatment regimen for MDR enteric fever, based on the double-drug synergy tests in vitro; Cp-gentamycin (FICI 0.121–0.216 and Cp-trimethoprim (FICI 0.14–0.483 combinations were found effective against S. Typhi isolates having decreased sensitivity to cp (MICs: 0.5–1.25 μg mL−1.

  20. Vigilancia de la resistencia de Neisseria gonorrhoeae en un hospital de la provincia de Santa Fe, Argentina: 1997-2004 Resistance surveillance of Neisseria gonorrhoeae in a hospital in Santa Fe province, Argentina: 1997-2004

    Directory of Open Access Journals (Sweden)

    E. De Los A. Méndez

    2008-09-01

    Full Text Available Se determinaron los fenotipos de resistencia caracterizados por la concentración inhibitoria mínima, la difusión con discos y la producción de β-lactamasa de 434 aislamientos de Neisseria gonorrhoeae obtenidos de pacientes atendidos en el Servicio de Enfermedades de Transmisión Sexual del Hospital Dr. José María Cullen, Santa Fe, Argentina. Se realizaron pruebas de sensibilidad a los siguientes antimicrobianos: penicilina, tetraciclina, ciprofloxacina, espectinomicina, azitromicina y ceftriaxona. A tres aislamientos resistentes a ciprofloxacina se les realizó electroforesis de campo pulsado. Se destacaron tres situaciones epidemiológicas de interés: en el año 1997, alta incidencia de aislamientos con resistencia plasmídica a tetraciclina (33,3%; en el período 2002-2004, un aumento significativo de la resistencia plasmídica a penicilina (9,7% a 34,8%; y en el año 2000, la emergencia de dos de los tres primeros aislamientos con resistencia a quinolonas del país. El primer aislamiento resistente a azitromicina en nuestro hospital emerge en el 2004. Este trabajo jerarquiza el rol del Laboratorio de Microbiología Clínica en la orientación del tratamiento empírico de la gonorrea.Resistance phenotypes characterized by minimum inhibitory concentration, disk diffusion and β-lactamase production were determined in 434 isolates from patients attending the Sexually Transmitted Disease Service at Dr. José María Cullen Hospital in Santa Fe, Argentina. Susceptibility tests to penicillin, tetracycline, ciprofloxacin, espectinomycin, azithromycin and ceftriaxone were performed. Pulsed-field gel electrophoresis was conducted made to on three ciprofloxacin-resistant isolates. Epidemiologically speaking, three interesting events should be highlighted: during 1997, plasmid-mediated high level tetracycline-resistant strains were observed (33.3%; from 2002 to 2004 a significant increase of plasmid-mediated penicillin-resistant strains was

  1. The identification of a tetracycline resistance gene tet(M), on a Tn916-like transposon, in the Bacillus cereus group

    DEFF Research Database (Denmark)

    Agersø, Yvonne; Jensen, Lars Bogø; Givskov, Michael Christian

    2002-01-01

    In order to investigate whether resistance genes present in bacteria in manure could transfer to indigenous soil bacteria, resistant isolates belonging to the Bacillus cereus group (Bacillus cereus, Bacillus anthracis and Bacillus thuringiensis) were isolated from farm soil (72 isolates) and manure...

  2. Abundances of tetracycline, sulphonamide and beta-lactam antibiotic resistance genes in conventional wastewater treatment plants (WWTPs) with different waste load

    DEFF Research Database (Denmark)

    Laht, Mailis; Karkman, Antti; Voolaid, Veiko

    2014-01-01

    Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs), an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs) were quantified using qPCR in three WWTPs of decreasing capacity located...... abundances with 16S rRNA gene abundances while assessing if the respective genes increased or decreased during treatment. ARGs were detected in most samples; sul1, sul2, and tetM were detected in all samples. Statistically significant differences (adjusted p... in the relative abundance of resistance genes, while the raw abundances fell by several orders of magnitude. Standard water quality variables (biological oxygen demand, total phosphorus and nitrogen, etc.) were weakly related or unrelated to the relative abundance of resistance genes. Based on our results we...

  3. Aminoglycoside resistance among isolates of nosocomial Enterobacteriaceae

    International Nuclear Information System (INIS)

    Botha, P.L.; Elisha, G.; Pratt, K.

    1981-01-01

    Fifty-seven gentamicin-resistant isolates of Enterobacteriaceae, obtained from patients attending hospital, were examined for the production of aminoglycoside-modifying enzymes. Of the 51 strains producing such enzymes, 34 were presumptively plasmid-mediated as indicated by conjugation experiments

  4. Outbreak of carbapenem-resistant Providencia rettgeri in a tertiary ...

    African Journals Online (AJOL)

    Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics ...

  5. Molecular characterization of multidrug-resistant Shigella spp. of food origin.

    Science.gov (United States)

    Ahmed, Ashraf M; Shimamoto, Tadashi

    2015-02-02

    Shigella spp. are the causative agents of food-borne shigellosis, an acute enteric infection. The emergence of multidrug-resistant clinical isolates of Shigella presents an increasing challenge for clinicians in the treatment of shigellosis. Several studies worldwide have characterized the molecular basis of antibiotic resistance in clinical Shigella isolates of human origin, however, to date, no such characterization has been reported for Shigella spp. of food origin. In this study, we characterized the genetic basis of multidrug resistance in Shigella spp. isolated from 1600 food samples (800 meat products and 800 dairy products) collected from different street venders, butchers, retail markets, and slaughterhouses in Egypt. Twenty-four out of 27 Shigella isolates (88.9%) showed multidrug resistance phenotypes to at least three classes of antimicrobials. The multidrug-resistant Shigella spp. were as follows: Shigella flexneri (66.7%), Shigella sonnei (18.5%), and Shigella dysenteriae (3.7%). The highest resistance was to streptomycin (100.0%), then to kanamycin (95.8%), nalidixic acid (95.8%), tetracycline (95.8%), spectinomycin (93.6%), ampicillin (87.5%), and sulfamethoxazole/trimethoprim (87.5%). PCR and DNA sequencing were used to screen and characterize integrons and antibiotic resistance genes. Our results indicated that 11.1% and 74.1% of isolates were positive for class 1 and class 2 integrons, respectively. Beta-lactamase-encoding genes were identified in 77.8% of isolates, and plasmid-mediated quinolone resistance genes were identified in 44.4% of isolates. These data provide useful information to better understand the molecular basis of antimicrobial resistance in Shigella spp. To the best of our knowledge, this is the first report of the molecular characterization of antibiotic resistance in Shigella spp. isolated from food. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Compound list: tetracycline [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available tetracycline TC 00048 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/...in_vitro/tetracycline.Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in..._vitro/tetracycline.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_viv...o/Liver/Single/tetracycline.Rat.in_vivo.Liver.Single.zip ftp://ftp.biosciencedbc.

  7. Increasing tetracycline concentrations on the performance and communities of mixed microalgae-bacteria photo-bioreactors

    KAUST Repository

    Xiong, Yanghui; Hozic, Dzenan; Goncalves, Ana L.; Simõ es, Manuel; Hong, Pei-Ying

    2017-01-01

    , however, increased in relative abundance, which correlated with an increase in the abundance of tetracycline resistance genes associated with efflux pump mechanism. Overall, the findings demonstrate that antibiotic concentrations in municipal wastewaters

  8. High diversity of genes and plasmids encoding resistance to third-generation cephalosporins and quinolones in clinical Escherichia coli from commercial poultry flocks in Italy

    DEFF Research Database (Denmark)

    Niero, Giulia; Bortolaia, Valeria; Vanni, Michele

    2018-01-01

    = 98) and layers (n = 22) between 2008 and 2012. 3GC-resistant isolates were screened for extended-spectrum and AmpC β-lactamase (ESBL/AmpC), while all isolates were tested for plasmid-mediated quinolone resistance (PMQR) genes. ESBL/AmpC- and PMQR-positive isolates were typed by pulsed-field gel......% of isolates from turkeys, broilers and layers, respectively. We identified seven ESBL/AmpC-encoding plasmid types, usually conjugative (78%), with a marked prevalence of IncI1/pST3 plasmids carrying blaCTX-M-1. PMQR occurred less frequently among isolates from turkeys (0.9%) compared to those from broilers (5......%) and layers (4%). The PMQR genes qnrS, qnrB19 and oqxA/B were located on three plasmid types and two non-typeable plasmids, mostly (85%) conjugative. ESBL/AmpC- and PMQR-positive isolates were genetically unrelated and 64% of them were additionally resistant to aminoglycosides, sulfonamides and tetracyclines...

  9. Tetracyclines function as dual-action light-activated antibiotics.

    Directory of Open Access Journals (Sweden)

    Ya He

    Full Text Available Antimicrobial photodynamic inactivation (aPDI employs photosensitizing dyes activated by visible light to produce reactive oxygen species. aPDI is independent of the antibiotic resistance status of the target cells, and is thought unlikely to produce resistance itself. Among many PS that have been investigated, tetracyclines occupy a unique niche. They are potentially dual-action compounds that can both kill bacteria under illumination, and prevent bacterial regrowth by inhibiting ribosomes. Tetracycline antibiotics are regarded as bacteriostatic rather than bactericidal. Doxycycline (DOTC is excited best by UVA light (365 nm while demeclocycline (DMCT can be efficiently activated by blue light (415 nm as well as UVA. Both compounds were able to eradicate Gram-positive (methicillin-resistant Staphylococcus aureus and Gram-negative (Escherichia coli bacteria (>6 log(10 steps of killing at concentrations (10-50μM and fluences (10-20J/cm2. In contrast to methylene blue, MB plus red light, tetracyclines photoinactivated bacteria in rich growth medium. When ~3 logs of bacteria were killed with DMCT/DOTC+light and the surviving cells were added to growth medium, further bacterial killing was observed, while the same experiment with MB allowed complete regrowth. MIC studies were carried out either in the dark or exposed to 0.5mW/cm2 blue light. Up to three extra steps (8-fold increased antibiotic activity was found with light compared to dark, with MRSA and tetracycline-resistant strains of E. coli. Tetracyclines can accumulate in bacterial ribosomes, where they could be photoactivated with blue/UVA light producing microbial killing via ROS generation.

  10. Antibiotic resistance genes in surface water of eutrophic urban lakes are related to heavy metals, antibiotics, lake morphology and anthropic impact.

    Science.gov (United States)

    Yang, Yuyi; Xu, Chen; Cao, Xinhua; Lin, Hui; Wang, Jun

    2017-08-01

    Urban lakes are impacted by heavy human activities and represent potential reservoirs for antibiotic resistance genes. In this study, six urban lakes in Wuhan, central China were selected to analyze the distribution of sulfonamide resistance (sul) genes, tetracycline resistance (tet) genes and quinolone resistance (qnr) genes and their relationship with heavy metals, antibiotics, lake morphology and anthropic impact. sul1 and sul2 were detected in all six lakes and dominated the types of antibiotic resistance genes, which accounted for 86.28-97.79% of the total antibiotic resistance gene abundance. For eight tested tet genes, antibiotic efflux pumps (tetA, tetB, tetC, and tetG) genes were all observed in six lakes and had higher relative abundance than ribosomal protection protein genes (tetM and tetQ). For 4 plasmid mediated quinolone resistance genes, only qnrD is found in all six lakes. The class I integron (intI1) is also found to be a very important media for antibiotic resistance gene propagation in urban lakes. The results of redundancy analysis and variation partitioning analysis showed that antibiotic and co-selection with heavy metals were the major factors driving the propagation of antibiotic resistance genes in six urban lakes. The heavily eutrophic Nanhu Lake and Shahu Lake which located in a high density building area with heavy human activities had the higher relative abundance of total antibiotic resistance genes. Our study could provide a useful reference for antibiotic resistance gene abundance in urban lakes with high anthropic impact.

  11. Increasing tetracycline concentrations on the performance and communities of mixed microalgae-bacteria photo-bioreactors

    KAUST Repository

    Xiong, Yanghui

    2017-12-11

    This study investigated the impact of varying concentrations of tetracycline on the performance of mixed microalgae-bacteria photo-bioreactors. Photo-bioreactors were assessed for their ability to remove carbon dioxide (CO2) from the biogas of anaerobic membrane bioreactor (anMBR), and nutrients from the anaerobic effluent. The varying concentrations of tetracycline had no impact on the removal of CO2 from biogas. 29% v/v of CO2 was completely removed to generate >20% v/v of oxygen (O2) in all reactors. Removal of nutrients and biomass was not affected at low concentrations of tetracycline (≤150μg/L), but 20mg/L of tetracycline lowered the biomass generation and removal efficiencies of phosphate. Conversely, high chlorophyll a and b content was observed at 20mg/L of tetracycline. High tetracycline level had no impact on the diversity of 18S rRNA gene-based microalgal communities but adversely affected the 16S rRNA gene-based microbial communities. Specifically, both Proteobacteria and Bacteroidetes phyla decreased in relative abundance but not phylum Chloroplast. Additionally, both nitrogen-fixing (e.g. Flavobacterium, unclassified Burkholderiales and unclassified Rhizobiaceae) and denitrifying groups (e.g. Hydrogenophaga spp.) were significantly reduced in relative abundance at high tetracycline concentration. Phosphate-accumulating microorganisms, Acinetobacter spp. and Pseudomonas spp. were similarly reduced upon exposure to high tetracycline concentration. Unclassified Comamonadaceae, however, increased in relative abundance, which correlated with an increase in the abundance of tetracycline resistance genes associated with efflux pump mechanism. Overall, the findings demonstrate that antibiotic concentrations in municipal wastewaters will not significantly affect the removal of nutrients by the mixed microalgae-bacteria photo-bioreactors. However, utilizing such photo-bioreactors as a polishing step for anMBRs that treat wastewaters with high tetracycline

  12. Whole-genome pyrosequencing of an epidemic multidrug-resistant Acinetobacter baumannii strain belonging to the European clone II group

    DEFF Research Database (Denmark)

    Iacono, M.; Villa, L.; Fortini, D.

    2008-01-01

    The whole-genome sequence of an epidemic, multidrug-resistant Acinetobacter baumannii strain (strain ACICU) belonging to the European clone II group and carrying the plasmid-mediated bla(OXA-58) carbapenem resistance gene was determined. The A. baumannii ACICU genome was compared with the genomes...

  13. Performance and microbial community variations of anaerobic digesters under increasing tetracycline concentrations

    KAUST Repository

    Xiong, Yanghui; Harb, Moustapha; Hong, Pei-Ying

    2017-01-01

    The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. Results revealed that for all of the tested tetracycline concentrations, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to the highest concentration of tetracycline (20 mg/L). Microbial community analyses suggest that an alternative methanogenic pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in volatile fatty acids (VFA)-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with ribosomal protection proteins was observed after 30 days of exposure to high concentrations of tetracycline, while other targeted resistance genes showed no significant changes. These findings suggest that anaerobic treatment processes can robustly treat wastewater with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.

  14. Performance and microbial community variations of anaerobic digesters under increasing tetracycline concentrations

    KAUST Repository

    Xiong, Yanghui

    2017-04-01

    The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. Results revealed that for all of the tested tetracycline concentrations, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to the highest concentration of tetracycline (20 mg/L). Microbial community analyses suggest that an alternative methanogenic pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in volatile fatty acids (VFA)-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with ribosomal protection proteins was observed after 30 days of exposure to high concentrations of tetracycline, while other targeted resistance genes showed no significant changes. These findings suggest that anaerobic treatment processes can robustly treat wastewater with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.

  15. Performance and microbial community variations of anaerobic digesters under increasing tetracycline concentrations.

    Science.gov (United States)

    Xiong, Yanghui; Harb, Moustapha; Hong, Pei-Ying

    2017-07-01

    The impact of different concentrations of tetracycline on the performance of anaerobic treatment was evaluated. Results revealed that for all of the tested tetracycline concentrations, no major sustained impact on methane production was observed. Instead, a significant increase in propionic acid was observed in the reactor subjected to the highest concentration of tetracycline (20 mg/L). Microbial community analyses suggest that an alternative methanogenic pathway, specifically that of methanol-utilizing methanogens, may be important for ensuring the stability of methane production in the presence of high tetracycline concentrations. In addition, the accumulation of propionate was due to an increase in volatile fatty acids (VFA)-producing bacteria coupled with a reduction in propionate utilizers. An increase in the abundance of tetracycline resistance genes associated with ribosomal protection proteins was observed after 30 days of exposure to high concentrations of tetracycline, while other targeted resistance genes showed no significant changes. These findings suggest that anaerobic treatment processes can robustly treat wastewater with varying concentrations of antibiotics while also deriving value-added products and minimizing the dissemination of associated antibiotic resistance genes.

  16. Biosolid-borne tetracyclines and sulfonamides in plants.

    Science.gov (United States)

    Mathews, Shiny; Reinhold, Dawn

    2013-07-01

    Tetracyclines and sulfonamides used in human and animal medicine are released to terrestrial ecosystems from wastewater treatment plants or by direct manure application. The interactions between plants and these antibiotics are numerous and complex, including uptake and accumulation, phytometabolism, toxicity responses, and degradation in the rhizosphere. Uptake and accumulation of antibiotics have been studied in plants such as wheat, maize, potato, vegetables, and ornamentals. Once accumulated in plant tissue, organic contaminants can be metabolized through a sequential process of transformation, conjugation through glycosylation and glutathione pathways, and ultimately sequestration into plant tissue. While studies have yet to fully elucidate the phytometabolism of tetracyclines and sulfonamides, an in-depth review of plant and mammalian studies suggest multiple potential transformation and conjugation pathways for tetracyclines and sulfonamides. The presence of contaminants in the vicinity or within the plants can elicit stress responses and defense mechanisms that can help tolerate the negative effects of contaminants. Antibiotics can change microbial communities and enzyme activity in the rhizosphere, potentially inducing microbial antibiotic resistance. On the other hand, the interaction of microbes and root exudates on pharmaceuticals in the rhizosphere can result in degradation of the parent molecule to less toxic compounds. To fully characterize the environmental impacts of increased antibiotic use in human medicine and animal production, further research is essential to understand the effects of different antibiotics on plant physiology and productivity, uptake, translocation, and phytometabolism of antibiotics, and the role of antibiotics in the rhizosphere.

  17. Resistance Pattern and Molecular Characterization of Enterotoxigenic Escherichia coli (ETEC Strains Isolated in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Yasmin A Begum

    Full Text Available Enterotoxigenic Escherichia coli (ETEC is a common cause of bacterial infection leading to acute watery diarrhea in infants and young children as well as in travellers to ETEC endemic countries. Ciprofloxacin is a broad-spectrum antimicrobial agent nowadays used for the treatment of diarrhea. This study aimed to characterize ciprofloxacin resistant ETEC strains isolated from diarrheal patients in Bangladesh.A total of 8580 stool specimens from diarrheal patients attending the icddr,b Dhaka hospital was screened for ETEC between 2005 and 2009. PCR and Ganglioside GM1- Enzyme Linked Immuno sorbent Assay (ELISA was used for detection of Heat labile (LT and Heat stable (ST toxins of ETEC. Antimicrobial susceptibilities for commonly used antibiotics and the minimum inhibitory concentration (MIC of nalidixic acid, ciprofloxacin and azithromycin were examined. DNA sequencing of representative ciprofloxacin resistant strains was performed to analyze mutations of the quinolone resistance-determining region of gyrA, gyrB, parC and parE. PCR was used for the detection of qnr, a plasmid mediated ciprofloxacin resistance gene. Clonal variations among ciprofloxacin resistant (CipR and ciprofloxacin susceptible (CipS strains were determined by Pulsed-field gel electrophoresis (PFGE.Among 1067 (12% ETEC isolates identified, 42% produced LT/ST, 28% ST and 30% LT alone. Forty nine percent (n = 523 of the ETEC strains expressed one or more of the 13 tested colonization factors (CFs as determined by dot blot immunoassay. Antibiotic resistance of the ETEC strains was observed as follows: ampicillin 66%, azithromycin 27%, ciprofloxacin 27%, ceftriazone 13%, cotrimaxazole 46%, doxycycline 44%, erythromycin 96%, nalidixic acid 83%, norfloxacin 27%, streptomycin 48% and tetracycline 42%. Resistance to ciprofloxacin increased from 13% in 2005 to 34% in 2009. None of the strains was resistant to mecillinam. The MIC of the nalidixic acid and ciprofloxacin of representative

  18. Assessment of antibiotic resistance genes and integrons in commensal Escherichia coli from the Indian urban waste water: Implications and significance for public health

    Directory of Open Access Journals (Sweden)

    Nambram Somendro Singh

    2017-10-01

    Full Text Available Antibiotics like β-lactams, quinolones/fluoroquinolones, aminoglycosides and tetracycline constitute the major mainstay of treatment against most infectious diseases including Escherichia coli. Indiscriminate use of antibiotics for human and animal well-being has generated an enormous evolutionary pressure on bacteria especially E.coli, which has a highly plastic/evolving genome. Though, antibiotic resistance (AR has been extensively studied in pathogenic E.coli, commensal strains have been studied less owing to lesser clinical significance. However, commensal strains pose a serious threat as reservoirs and transmitters of resistance genes to other bacteria. Therefore, the present study was undertaken to investigate the prevalence of resistance genes and integrons in commensal E.coli isolated from river Yamuna, Delhi, India, which receives plentiful urban waste water. Eighty three well-characterized E.coli strains of phylogroups A and B1 isolated from river Yamuna were investigated. Antimicrobial susceptibilities and minimal inhibitory concentrations (MICs for β-lactams, aminoglycosides, tetracycline and quinolone/fluoroquinolone were determined by disk diffusion and Etest, according to Clinical and Laboratory Standards Institute (CLSI guidelines. Production of Extended spectrum β-lactamases (ESBL and AmpC was investigated. Prevalence of antibiotic-resistance genes for β-lactams (blaTEM,blaSHV, blaCTX-M, blaOXA, blaCMY-42, aminoglycosides (rmtA, rmtB, rmtC, armA, str, aacC2, tetracycline (tetA, tetR, tetM, tetW, and plasmid-mediated quinolone resistance, PMQR (qnrA, qnrB, qnrC, qnrD, qnrS, qep, aac were assessed. Integrons and  gene-cassette arrays were characterized. Commensal E.coli strains showed a higher resistance to ampicillin (95%, less to cefazolin (45% and still lesser to tetracycline (15%. About 19% of these strains showed multidrug resistant (three or more classes of antibiotics, of which 15% also produced ESBLs. None of the

  19. Molecular study on some antibiotic resistant genes in Salmonella spp. isolates

    Science.gov (United States)

    Nabi, Ari Q.

    2017-09-01

    Studying the genes related with antimicrobial resistance in Salmonella spp. is a crucial step toward a correct and faster treatment of infections caused by the pathogen. In this work Integron mediated antibiotic resistant gene IntI1 (Class I Integrase IntI1) and some plasmid mediated antibiotic resistance genes (Qnr) were scanned among the isolated non-Typhoid Salmonellae strains with known resistance to some important antimicrobial drugs using Sybr Green real time PCR. The aim of the study was to correlate the multiple antibiotics and antimicrobial resistance of Salmonella spp. with the presence of integrase (IntI1) gene and plasmid mediated quinolone resistant genes. Results revealed the presence of Class I Integrase gene in 76% of the isolates with confirmed multiple antibiotic resistances. Moreover, about 32% of the multiple antibiotic resistant serotypes showed a positive R-PCR for plasmid mediated qnrA gene encoding for nalidixic acid and ciprofloxacin resistance. No positive results could be revealed form R-PCRs targeting qnrB or qnrS. In light of these results we can conclude that the presence of at least one of the qnr genes and/or the presence of Integrase Class I gene were responsible for the multiple antibiotic resistance to for nalidixic acid and ciprofloxacin from the studied Salmonella spp. and further studies required to identify the genes related with multiple antibiotic resistance of the pathogen.

  20. Phenotypic and molecular characterization of antimicrobial resistance in Enterobacter spp. isolates from companion animals in Japan.

    Science.gov (United States)

    Harada, Kazuki; Shimizu, Takae; Mukai, Yujiro; Kuwajima, Ken; Sato, Tomomi; Kajino, Akari; Usui, Masaru; Tamura, Yutaka; Kimura, Yui; Miyamoto, Tadashi; Tsuyuki, Yuzo; Ohki, Asami; Kataoka, Yasushi

    2017-01-01

    The emergence of antimicrobial resistance among Enterobacter spp., including resistance to extended-spectrum cephalosporins (ESC), is of great concern in both human and veterinary medicine. In this study, we investigated the prevalence of antimicrobial resistance among 60 isolates of Enterobacter spp., including E. cloacae (n = 44), E. aerogenes (n = 10), and E. asburiae (n = 6), from clinical specimens of dogs and cats from 15 prefectures in Japan. Furthermore, we characterized the resistance mechanisms harbored by these isolates, including extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR); and assessed the genetic relatedness of ESC-resistant Enterobacter spp. strains by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Antimicrobial susceptibility testing demonstrated the resistance rates to ampicillin (93.3%), amoxicillin-clavulanic acid (93.3%), cefmetazole (93.3%), chloramphenicol (46.7%), ciprofloxacin (43.3%), tetracycline (40.0%), ceftazidime (33.3%), cefotaxime (33.3%), trimethoprim/sulfamethoxazole (28.3%), gentamicin (23.3%), and meropenem (0%). Phenotypic testing detected ESBLs in 16 of 18 ESC-resistant E. cloacae isolates but not in the other species. The most frequent ESBL was CTX-M-15 (n = 8), followed by SHV-12 (n = 7), and CTX-M-3 (n = 1). As for AmpC β-lactamases, CMY-2 (n = 2) and DHA-1 (n = 2) were identified in ESC-resistant E. cloacae strains with or without ESBLs. All of the ESC-resistant E. cloacae strains also harbored one or two PMQRs, including qnrB (n = 15), aac(6')-Ib-cr (n = 8), and qnrS (n = 2). Based on MLST and PFGE analysis, E. cloacae clones of ST591-SHV-12, ST171-CTX-M-15, and ST121-CTX-M-15 were detected in one or several hospitals. These results suggested intra- and inter-hospital dissemination of E. cloacae clones co-harboring ESBLs and PMQRs among companion animals. This is the first report on the large-scale monitoring of antimicrobial-resistant isolates

  1. Diversity of the Tetracycline Mobilome within a Chinese Pig Manure Sample.

    Science.gov (United States)

    Leclercq, Sébastien Olivier; Wang, Chao; Zhu, Yaxin; Wu, Hai; Du, Xiaochen; Liu, Zhipei; Feng, Jie

    2016-11-01

    Tetracycline antibiotics are widely used in livestock, and tetracycline resistance genes (TRG) are frequently reported in the manure of farmed animals. However, the diversity of TRG-carrying transposons in manure has still been rarely investigated. Using a culture-free functional metagenomic procedure, combined with large-insert library construction and sequencing, bioinformatic analyses, and functional experiments, we identified 17 distinct TRGs in a single pig manure sample, including two new tet genes: tet(59), encoding a tetracycline efflux pump, and tet(W/N/W), encoding mosaic ribosomal protection. Our study also revealed six new TRG-carrying putative nonconjugative transposons: Tn5706-like transposon Tn6298, IS200/605-related transposon Tn6303, Tn3 family transposon Tn6299, and three ISCR2-related transposons, Tn62300, Tn62301, and Tn62302 IMPORTANCE: Fertilization of agricultural fields with animal manure is believed to play a major role in antibiotic resistance dissemination in the environment. There is growing concern for the possible spread of antibiotic resistance from the environment to humans since genetic resistance determinants may be located in transposons and other mobile genetic elements potentially transferable to pathogens. Among the various antibiotic resistance genes found in manure, tetracycline resistance genes (TRGs) are some of the most common. The present study provides a detailed snapshot of the tetracycline mobilome in a single pig manure sample, revealing an unappreciated diversity of TRGs and potential TRG mobility vectors. Our precise identification of the TRG-carrying units will enable us to investigate in more details their mobility effectiveness. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  2. New plasmid-mediated aminoglycoside 6'-N-acetyltransferase, AAC(6')-Ian, and ESBL, TLA-3, from a Serratia marcescens clinical isolate.

    Science.gov (United States)

    Jin, Wanchun; Wachino, Jun-Ichi; Kimura, Kouji; Yamada, Keiko; Arakawa, Yoshichika

    2015-05-01

    Enterobacteriaceae clinical isolates showing amikacin resistance (MIC 64 to >256 mg/L) in the absence of 16S rRNA methyltransferase (MTase) genes were found. The aim of this study was to clarify the molecular mechanisms underlying amikacin resistance in Enterobacteriaceae clinical isolates that do not produce 16S rRNA MTases. PCR was performed to detect already-known amikacin resistance determinants. Cloning experiments and sequence analyses were performed to characterize unknown amikacin resistance determinants. Transfer of amikacin resistance determinants was performed by conjugation and transformation. The complete nucleotide sequence of the plasmids was determined by next-generation sequencing technology. Amikacin resistance enzymes were purified with a column chromatography system. The enzymatic function of the purified protein was investigated by thin-layer chromatography (TLC) and HPLC. Among the 14 isolates, 9 were found to carry already-known amikacin resistance determinants such as aac(6')-Ia and aac(6')-Ib. Genetic analyses revealed the presence of a new amikacin acetyltransferase gene, named aac(6')-Ian, located on a 169 829 bp transferable plasmid (p11663) of the Serratia marcescens strain NUBL-11663, one of the five strains negative for known aac(6') genes by PCR. Plasmid p11663 also carried a novel ESBL gene, named blaTLA-3. HPLC and TLC analyses demonstrated that AAC(6')-Ian catalysed the transfer of an acetyl group from acetyl coenzyme A onto an amine at the 6'-position of various aminoglycosides. We identified aac(6')-Ian as a novel amikacin resistance determinant together with a new ESBL gene, blaTLA-3, on a transferable plasmid of a S. marcescens clinical isolate. © 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.

  3. 21 CFR 556.720 - Tetracycline.

    Science.gov (United States)

    2010-04-01

    ..., FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.720 Tetracycline. (a) Acceptable daily intake (ADI). The ADI for total... tissues of calves, swine, sheep, chickens, and turkeys, of 2 parts per million (ppm) in muscle, 6 ppm in...

  4. Characteristics of plasmids in multi-drug-resistant Enterobacteriaceae isolated during prospective surveillance of a newly opened hospital in Iraq.

    Directory of Open Access Journals (Sweden)

    Xiao-Zhe Huang

    Full Text Available BACKGROUND: Gram-negative multidrug-resistant (MDR bacteria are major causes of nosocomial infections, and antibiotic resistance in these organisms is often plasmid mediated. Data are scarce pertaining to molecular mechanisms of antibiotic resistance in resource constrained areas such as Iraq. METHODOLOGY/PRINCIPAL FINDINGS: In this study, all MDR Enterobacteriaceae (n = 38 and randomly selected non-MDR counterparts (n = 41 isolated from patients, healthcare workers and environmental surfaces in a newly opened hospital in Iraq were investigated to characterize plasmids found in these isolates and determine their contribution to antibiotic resistance. Our results demonstrated that MDR E. coli and K. pneumoniae isolates harbored significantly more (≥ 3 plasmids compared to their non-MDR counterparts, which carried ≤ 2 plasmids (p<0.01. Various large plasmids (~52 to 100 kb from representative isolates were confirmed to contain multiple resistance genes by DNA microarray analysis. Aminoglycoside (acc, aadA, aph, strA/B, and ksgA, β-lactam (bla(TEM1, bla(AMPC, bla(CTX-M-15, bla(OXA-1, bla(VIM-2 and bla(SHV, sulfamethoxazole/trimethoprim (sul/dfr, tetracycline (tet and chloramphenicol (cat resistance genes were detected on these plasmids. Additionally, multiple plasmids carrying multiple antibiotic resistance genes were found in the same host strain. Genetic transfer-associated genes were identified on the plasmids from both MDR and non-MDR isolates. Seven plasmid replicon types (FII, FIA, FIB, B/O, K, I1 and N were detected in the isolates, while globally disseminated IncA/C and IncHI1 plasmids were not detected in these isolates. CONCLUSIONS/SIGNIFICANCE: This is the first report of the characteristics of the plasmids found in Enterobacteriaceae isolated following the opening of a new hospital in Iraq. The information provided here furthers our understanding of the mechanisms of drug resistance in this specific region and their evolutionary

  5. Influence of montmorillonite on antimicrobial activity of tetracycline and ciprofloxacin

    Science.gov (United States)

    Lv, Guocheng; Pearce, Cody W.; Gleason, Andrea; Liao, Libing; MacWilliams, Maria P.; Li, Zhaohui

    2013-11-01

    Antibiotics are used not only to fight infections and inhibit bacterial growth, but also as growth promotants in farm livestock. Farm runoff and other farm-linked waste have led to increased antibiotic levels present in the environment, the impact of which is not completely understood. Soil, more specifically clays, that the antibiotic contacts may alter its effectiveness against bacteria. In this study a swelling clay mineral montmorillonite was preloaded with antibiotics tetracycline and ciprofloxacin at varying concentrations and bioassays were conducted to examine whether the antibiotics still inhibited bacterial growth in the presence of montmorillonite. Escherichia coli was incubated with montmorillonite or antibiotic-adsorbed montmorillonite, and then the number of viable bacteria per mL was determined. The antimicrobial activity of tetracycline was affected in the presence of montmorillonite, as the growth of non-resistant bacteria was still found even when extremely high TC doses were used. Conversely, in the presence of montmorillonite, ciprofloxacin did inhibit E. coli bacterial growth at high concentrations. These results suggest that the effectiveness of antimicrobial agents in clayey soils depends on the amount of antibiotic substance present, and on the interactions between the antibiotic and the clays in the soil, as well.

  6. Development of a radioimmunoassay of tetracycline and its derivatives

    International Nuclear Information System (INIS)

    Zitzewitz, A. von.

    1981-01-01

    A radioimmunoassay for tetracycline was developed in the context of the present work. The determination of tetracycline content in biological samples is to be made valid using tetracycline RIA. As well as the carbodiimide method, a by radioimmunologists extremely seldomly used way involving a condensation reaction between protein and haptene via the Mannich reaction was successfully applied. Antibodies were produced using a conventional immunisation method after Abraham, the other applied alternative method after Vaitukaitis et al. The general working methods had to be adapted to the tetracycline RIA. All variable parameters of the antigen-antibody bond were tested to optimize the incubation conditions of the system as well as to control the tracer for a degradation. The detection limit of RIA is 10 - 12 , the measuring range from 10 - 12 to 10 - 10 mol for tetracycline hydrochloride and rolitetracycline respectively and up to 10 - 9 mol for its derivates. The investigations for cross reactions showed a high specificity for tetracycline (100%) and its intravenously appliable pyrrolidino-methyl derivative rolitetracycline (88%). Standard curves could be drawn up using either of the two compounds tetracycline and rolitetracycline as standard. The pharmaco-kinetic behaviour of the parenteral administrable tetracycline was analyzed as example for the possible applications of the tetracycline radioimmunoassay. Parallel animal tests administring 3 H tetracycline hydrochloride were performed for radioimmunoassay reference. The possible application of tetracycline radioimmunoassay in food analysis is discussed. (orig./MG) [de

  7. Sorption of tetracycline on organo-montmorillonites

    International Nuclear Information System (INIS)

    Liu, Niu; Wang, Ming-xia; Liu, Ming-ming; Liu, Fan; Weng, Liping; Koopal, Luuk K.; Tan, Wen-feng

    2012-01-01

    Highlights: ► The sorption capacity of tetracycline on Mont. modified with QACs was highly promoted. ► Tetracycline adsorbed on organoclay was affected by the amount and the length of QACs. ► Tetracycline adsorption on organoclay exhibited high pH-dependence below 5. - Abstract: Tetracycline (TC) is a veterinary antibiotic that is frequently detected as pollutant in the environment. Powerful adsorbents are required for removing TC. The present paper compares the TC adsorption capacity of Na-montmorillonite (Na-mont) with six organo-montmorillonites (organo-monts). Three quaternary ammonium cations (QACs) with different alkyl-chain lengths were used as modifiers. Powder X-ray diffraction indicated that the d 001 values of organo-monts increased with increasing the QACs loading and alkyl-chain length. The CECs of the organo-monts were substantially lower than that of Na-mont and decreased with QACs chain length and increased loading. The modeling of the adsorption kinetics revealed that the processes of TC adsorption on the tested samples could be well fitted by the pseudo-second-order equation. The maximum adsorption capacities of TC on the organo-monts (1000–2000 mmol/kg) were considerably higher than that on Na-mont (769 mmol/kg). Both the Langmuir and Freundlich model could fit the adsorption isotherms. The TC adsorption to the organo-monts increase significantly with decreasing the pH below 5.5 because of the electrostatic interaction, and a high QACs loading performed better than a low loading at around pH 3.

  8. A new tetracycline efflux gene, tet(40), is located in tandem with tet(O/32/O) in a human gut firmicute bacterium and in metagenomic library clones.

    Science.gov (United States)

    Kazimierczak, Katarzyna A; Rincon, Marco T; Patterson, Andrea J; Martin, Jennifer C; Young, Pauline; Flint, Harry J; Scott, Karen P

    2008-11-01

    The bacterium Clostridium saccharolyticum K10, isolated from a fecal sample obtained from a healthy donor who had received long-term tetracycline therapy, was found to carry three tetracycline resistance genes: tet(W) and the mosaic tet(O/32/O), both conferring ribosome protection-type resistance, and a novel, closely linked efflux-type resistance gene designated tet(40). tet(40) encodes a predicted membrane-associated protein with 42% amino acid identity to tetA(P). Tetracycline did not accumulate in Escherichia coli cells expressing the Tet(40) efflux protein, and resistance to tetracycline was reduced when cells were incubated with an efflux pump inhibitor. E. coli cells carrying tet(40) had a 50% inhibitory concentration of tetracycline of 60 microg/ml. Analysis of a transconjugant from a mating between donor strain C. saccharolyticum K10 and the recipient human gut commensal bacterium Roseburia inulinivorans suggested that tet(O/32/O) and tet(40) were cotransferred on a mobile element. Sequence analysis of a 37-kb insert identified on the basis of tetracycline resistance from a metagenomic fosmid library again revealed a tandem arrangement of tet(O/32/O) and tet(40), flanked by regions with homology to parts of the VanG operon previously identified in Enterococcus faecalis. At least 10 of the metagenomic inserts that carried tet(O/32/O) also carried tet(40), suggesting that tet(40), although previously undetected, may be an abundant efflux gene.

  9. Cotrimoxazole Resistant Chancroid

    Directory of Open Access Journals (Sweden)

    Kamlender Singh

    1985-01-01

    Full Text Available Four male young adults, after contact with prostitutes, developed clinically typical chancroid which was resistant to cotrimoxazole alone and also in combination with tetracycline. With chloramphenicol, the response was quick and complete with no untoward side effects.

  10. Assessment of oxytetracycline and tetracycline antibiotics in manure samples in different cities of Khuzestan Province, Iran.

    Science.gov (United States)

    Alavi, Nadali; Babaei, Ali Akbar; Shirmardi, Mohammad; Naimabadi, Abolfazl; Goudarzi, Gholamreza

    2015-11-01

    Tetracyclines (TCs), a class of antibiotics with a broad spectrum, are the most frequently used antibiotics in animal production. The major concern is that the widespread use of the antibiotics may lead to the emergence of new strains of bacteria that are resistant to these antibiotics. The objective of this study was to determine the residual levels of oxytetracycline and tetracycline in 80 animal manure samples that were collected from the livestock and poultry feedlots in Khuzestan Province. The residual levels of the antibiotics in the samples were extracted by using solid-phase extraction (SPE) method and subsequently were measured by liquid chromatography. Recoveries from the spiked poultry manure samples ranged from 65 to 113% for tetracycline and 86 to 132% for oxytetracycline. Relative standard deviations of the recoveries were less than 5.7% within the same day. Method detection limit (MDL) measured for oxytetracycline and tetracycline in the manure were 0.011 and 0.01 mg/kg, respectively. Analysis of the collected 50 chickens and 30 cow manure samples showed that the highest concentration of tetracycline was related to Behbahan City (5.36 mg/kg) and the lowest concentration was detected for Ramhormoz (0.05 mg/kg). The highest and lowest concentrations of oxytetracycline were respectively observed for Behbahan (13.77 mg/kg) and Ramhormoz (0.047 mg/kg). Based on the results, in chicken manure, there was significant statistical difference between the residual TC concentrations among five cities (p(value) oxytetracyclin (OTC) residual concentrations among five cities (p(value) > 0.05).

  11. In vitro activity of five tetracyclines and some other antimicrobial agents against four porcine respiratory tract pathogens.

    Science.gov (United States)

    Pijpers, A; Van Klingeren, B; Schoevers, E J; Verheijden, J H; Van Miert, A S

    1989-09-01

    The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.

  12. Antimicrobial susceptibility pattern and plasmid-mediated ...

    African Journals Online (AJOL)

    negative Staphylococci (CoNS) were isolated from clinical samples and isolates subjected to antibiotic susceptibility testing, plasmid curing and plasmid DNA isolation. Result: The highest percentages isolates were recovered from urine samples and ...

  13. Ceftriaxone and tetracycline effect on biofilm-formation strains of Staphylococcus epidermidis

    Directory of Open Access Journals (Sweden)

    O. I. Sidashenko

    2014-04-01

    Full Text Available 122 strains of staphylococci were identified. Among the examined 122 clinical strains of staphylococci, 67 strains belonged to coagulase-positive, and 55 strains to the coagulase-negative ones. According to the study of physiological and biochemical properties, it was found that 37 strains (30.3% belonged to S. epidermidis species. One of the biological properties of many bacteria is the ability to film formation and these strains attract special attention, since it is known that the film antibiotic resistance is higher than in planktonic cultures. It was determined that 20 strains of those under study were film-forming, 17 strains – non-biofilm forming ones. The film was formed during three days, and settled to the bottom of the plate holes. The clinical (Cl strain of S. epidermidis was sensitive to ceftriaxone and tetracicline. The control (C strains of S. epidermidis were sensitive to ceftriaxone, tetracycline and sizomicine. The study of biofilm growth for 2, 3 and 4 days of incubation was carried out. The maximum rate of biofilm S. epidermidis C was observed during 2–3 days; there is the most intense increase of cells number from 5.2 × 108 CFU/ml, for S. epidermidis Cl to 5.6 × 108 CFU/ml. The effect of ceftriaxone and tetracycline on biofilm formation by 2 investigation strains of S. epidermidis was found. We determined differences in minimal inhibitory concentrations (MIC for planktonic cultures and biofilm of strains under study. It was established that MIC antibiotics inhibited the growth of planktonic cultures on average 2 times lower compared to the MIC which inhibited the biofilm formation. MIC for planktonic culture of S. epidermidis Cl defined for ceftriaxone was equal to 10 mg/ml, and for tetracycline – 1 mg/ml. MIC of ceftriaxone for the control strain was equal to 12 mg/ml, MIC of tetracycline – 0.7 mg/ml. MIC values for dynamics biofilm formation of S. epidermidis Cl strain on the plater were as follows: to

  14. Reactivities of tetracycline and oxytetracycline with OH radicals

    Energy Technology Data Exchange (ETDEWEB)

    Dziegielewski, J O; Glowacki, P [Uniwersytet Slaski, Katowice (Poland)

    1982-05-03

    Decomposition yields of tetracycline sulphate and oxytetracycline sulphate were determined in argon saturated 0.1N H/sub 2/SO/sub 4/ solutions. The decomposition yields of teracyclines decrease in the presence of the Cl/sup -/ ions. The reaction rate constants of the OH radicals with tetracyclines were also determined.

  15. Reactivities of tetracycline and oxytetracycline with OH radicals

    International Nuclear Information System (INIS)

    Dziegielewski, J.O.; Glowacki, P.

    1982-01-01

    Decomposition yields of tetracycline sulphate and oxytetracycline sulphate were determined in argon saturated 0.1N H 2 SO 4 solutions. The decomposition yields of teracyclines decrease in the presence of the Cl - ions. The reaction rate constants of the OH radicals with tetracyclines were also determined. (author)

  16. Tetracycline treatment of periodontal disease in the beagle dog

    Energy Technology Data Exchange (ETDEWEB)

    Jeffcoat, M.K.; Williams, R.C.; Kaplan, M.L.; Goldhaber, P.

    1982-01-01

    Bone-seeking radiopharmaceutical uptake (BSRU) was used to examine alveolar bone metabolism in a longitudinal study of tetracycline efficacy in beagle dogs. BSRU was measured in untreated control dogs and in beagles receiving either 250 mg or 500 mg oral tetracycline-HCl daily for 16 months. The rate of bone loss was determined for radiographs taken semiannually for a 6-month pretreatment period and for a 24-month treatment period. Measurements of BSRU obtained at month 16 of treatment were correlated with rates of bone loss determined radiographically in an attempt to determine whether BSRU was indicative of the subsequent rate of bone loss. A reduced rate of alveolar bone loss was found in the 500 mg tetracycline group at month 16 of the study relative to the untreated controls which was consistent with the decreased bone-seeking radiopharmaceutical uptake observed in this group. A significantly increased BSRU (p<.0001) was found in the 250 mg tetracycline group at month 16 of study relative to the untreated and 500 mg tetracycline groups. A rapid increase in the rate of bone loss in the 250 mg tetracycline group which was not detectable prior to 16 months of treatment became evident radiographically by 24 months. Thus, increased BSRU in the 250 mg tetracycline group appeared to detect the loss of the effect of tetracycline (escape phenomenon). 13 references, 4 figures.

  17. Ligand Binding Domain Protein in Tetracycline-Inducible Expression

    African Journals Online (AJOL)

    Purpose: To investigate tetracycline-inducible expression system for producing clinically usable, highquality liver X receptor ligand-binding domain recombinant protein. Methods: In this study, we have expressed and purified the recombinant liver X receptor β-ligand binding domain proteins in E. coli using a tetracycline ...

  18. Synergistic Efficacy of Aedes aegypti Antimicrobial Peptide Cecropin A2 and Tetracycline against Pseudomonas aeruginosa

    Science.gov (United States)

    Zheng, Zhaojun; Tharmalingam, Nagendran; Liu, Qingzhong; Kim, Wooseong; Fuchs, Beth Burgwyn; Zhang, Rijun; Vilcinskas, Andreas

    2017-01-01

    ABSTRACT The increasing prevalence of antibiotic resistance has created an urgent need for alternative drugs with new mechanisms of action. Antimicrobial peptides (AMPs) are promising candidates that could address the spread of multidrug-resistant bacteria, either alone or in combination with conventional antibiotics. We studied the antimicrobial efficacy and bactericidal mechanism of cecropin A2, a 36-residue α-helical cationic peptide derived from Aedes aegypti cecropin A, focusing on the common pathogen Pseudomonas aeruginosa. The peptide showed little hemolytic activity and toxicity toward mammalian cells, and the MICs against most clinical P. aeruginosa isolates were 32 to 64 μg/ml, and its MICs versus other Gram-negative bacteria were 2 to 32 μg/ml. Importantly, cecropin A2 demonstrated synergistic activity against P. aeruginosa when combined with tetracycline, reducing the MICs of both agents by 8-fold. The combination was also effective in vivo in the P. aeruginosa/Galleria mellonella model (P < 0.001). We found that cecropin A2 bound to P. aeruginosa lipopolysaccharides, permeabilized the membrane, and interacted with the bacterial genomic DNA, thus facilitating the translocation of tetracycline into the cytoplasm. In summary, the combination of cecropin A2 and tetracycline demonstrated synergistic antibacterial activity against P. aeruginosa in vitro and in vivo, offering an alternative approach for the treatment of P. aeruginosa infections. PMID:28483966

  19. Tetracycline is back. Three-step tetracycline-biotin tumour targeting

    International Nuclear Information System (INIS)

    Salehi, N.; Lichtenstein, M.

    1998-01-01

    Full text: In the 1960s, investigators attempted to use radiolabelled tetracycline for the detection of tumours. This was limited by bone and gastrointestinal uptake. The monoclonal antibody Avidin Biotin technology has been used for 10 years to target tumours. We have improved a novel mechanism using three step targeting, to demonstrate tumour cells in (C57B1/6X balb-c) F1 mice with subcutaneously implanted E-3 thymoma. The three steps were (1) i.p. injection of Biotin Tetracycline conjugate (t:1) ratio, (2) 96 h later Avidin was injected, and (3) 24 h after (2) 99m Tc-CDTPA-Biotin was injected. Avidin has four high affinity (Km 10-15) Biotin binding sites, hence step (2) couples the Avidin to Tetracycline-Biotin in the tumour. The Avidin then provides a high affinity target for the otherwise rapidly urinary excreted 99m Tc-CDTPA-Biotin. Mice were sacrificed 16-24h after (3) by cervical dislocation. Biodistribution of radioactivity tumour to blood, liver, bone and stomach were: T:BL= 7.2, T:LI= 3.35, TBO= 9.65, T:ST= 0.93. The percentage of injected dose/g was T = 4.49%, BL = 0.62%. E-3 Thymoma is a rapid growing tumour. At day 1 (step 1) the tumour size was 0.45 cm, six days later (step 3) each dimension was doubled. Hence, percentage of injected dose per gram is artefactually reduced eight-fold. With a slowly growing tumour using the same method the results may be better. The conclusions reached are that Tetracycline-Biotin 3-stage method of tumour targeting is worthy of further development

  20. Are Sewage Treatment Plants Promoting Antibiotic Resistance?

    Science.gov (United States)

    1. Introduction 1.1. How bacteria exhibit resistance 1.1.1. Resistance to -lactams 1.1.2. Resistance to sulphonamides and trimethoprim 1.1.3. Resistance to macrolides 1.1.4. Resistance to fluoroquinolones 1.1.5. Resistance to tetracyclines 1.1.6. Resistance to nitroimidaz...

  1. An overview of the main foodstuff sample preparation technologies for tetracycline residue determination.

    Science.gov (United States)

    Pérez-Rodríguez, Michael; Pellerano, Roberto Gerardo; Pezza, Leonardo; Pezza, Helena Redigolo

    2018-05-15

    Tetracyclines are widely used for both the treatment and prevention of diseases in animals as well as for the promotion of rapid animal growth and weight gain. This practice may result in trace amounts of these drugs in products of animal origin, such as milk and eggs, posing serious risks to human health. The presence of tetracycline residues in foods can lead to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. In order to ensure food safety and avoid exposure to these substances, national and international regulatory agencies have established tolerance levels for authorized veterinary drugs, including tetracycline antimicrobials. In view of that, numerous sensitive and specific methods have been developed for the quantification of these compounds in different food matrices. One will note, however, that the determination of trace residues in foods such as milk and eggs often requires extensive sample extraction and preparation prior to conducting instrumental analysis. Sample pretreatment is usually the most complicated step in the analytical process and covers both cleaning and pre-concentration. Optimal sample preparation can reduce analysis time and sources of error, enhance sensitivity, apart from enabling unequivocal identification, confirmation and quantification of target analytes. The development and implementation of more environmentally friendly analytical procedures, which involve the use of less hazardous solvents and smaller sample sizes compared to traditional methods, is a rapidly increasing trend in analytical chemistry. This review seeks to provide an updated overview of the main trends in sample preparation for the determination of tetracycline residues in foodstuffs. The applicability of several extraction and clean-up techniques employed in the analysis of foodstuffs, especially milk and egg samples, is also thoroughly discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Tetracycline and trimethoprim/sulfamethoxazole at clinical laboratory: can they help to characterize Staphylococcus aureus carrying different SCCmec types?

    Science.gov (United States)

    Cavalcante, Fernanda Sampaio; Schuenck, Ricardo Pinto; Caboclo, Roberta Mello Ferreira; Ferreira, Dennis de Carvalho; Nouér, Simone Aranha; Santos, Kátia Regina Netto dos

    2013-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) can be difficult to detect at the clinical practice. We analyzed 140 MRSA isolates from inpatients to correlate the antimicrobial susceptibility with the SCCmec types. Type III (n = 63) isolates were more resistant to ciprofloxacin, clindamycin, cloramphenicol, erythromycin, gentamicin, and rifampin than type IV (n = 65) ones (p < 0.05). Moreover, type IV isolates were susceptible to tetracycline (100%) and trimethoprim/sulfamethoxazole (98%), while type III isolates presented resistance to them. In regions where these SCCmec types are prevalent, the detection of specific resistant phenotypes could help to predict them, mainly when there are no technical conditions to SCCmec typing.

  3. Antimicrobial-resistant Shigella infections from Iran

    DEFF Research Database (Denmark)

    Tajbakhsh, Mercedeh; García Migura, Lourdes; Rahbar, Mohammad

    2012-01-01

    Objectives: In this study, we wanted to assess the level of antimicrobial resistance, the presence of genes encoding resistance to cephalosporins and plasmid-mediated quinolone resistance (PMQR), and genetic relatedness among Shigella isolates obtained from Iranian patients. ; Methods: A total...... of 44 Shigella isolates were collected from Iranian patients admitted to Milad Hospital, Tehran, Iran, during 2008–10. Of these, 37 were serotyped and characterized by MIC determination. A subset of eight suspected extended-spectrum β-lactamase (ESBL) producers (six Shigella sonnei phase II and two...... Shigella flexneri type 1b) were examined for the presence of genes encoding cephalosporin resistance. The presence of PMQR was assessed in one S. flexneri isolate exhibiting low-level resistance to ciprofloxacin and susceptibility to nalidixic acid. PFGE was performed on 25 S. sonnei phase II isolates...

  4. Ligand Binding Domain Protein in Tetracycline-Inducible Expression ...

    African Journals Online (AJOL)

    binding domain proteins in E. coli using a tetracycline inducible system. To allow for ... development of molecular ligands with improved therapeutic windows. Keywords: Nuclear receptor ..... functional recombinant cannabinoid receptor CB2 in ...

  5. Silica Nanofibers with Immobilized Tetracycline for Wound Dressing

    Directory of Open Access Journals (Sweden)

    Irena Lovětinská-Šlamborová

    2016-01-01

    Full Text Available Local antibiotic treatment has its justification for superficial infections. The advantage of this treatment is that the antibiotic has effects on bacterial agent directly at the application site. Skin infections which are intended for the local antibiotic treatment are superficial pyoderma, some festering wounds, burns of second and third degree, infected leg ulcers, or decubitus of second and third degree. Tetracyclines are available topical antibiotics with a broad bacterial spectrum. At present, ointments containing tetracycline are also used for the treatment, which rarely can lead to skin sensitization. In this paper, a development of novel nanofibrous material with immobilized tetracycline is presented. Two different methods of immobilized tetracycline quantification onto silica nanofibers are employed. It was proven that the prevailing part of tetracycline was bound weakly by physisorption forces, while the minor part was covalently bound by NH2 groups formed by the preceding functionalization. The silica nanofibers with immobilized tetracycline are promising material for wound dressing applications due to its antibacterial activity; it was proved by tests.

  6. Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wanru, Chen [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Huang, Ching-Hua [School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-05-15

    Tetracycline antibiotics including tetracycline (TTC), oxytetracycline (OTC) and chlorotetracycline (CTC) undergo rapid transformation to yield various products in the presence of MnO{sub 2} at mild conditions (pH 4-9 and 22 {sup o}C). Reaction rates follow the trend of CTC > TTC > OTC, and are affected by pH and complexation of TCs with Mg{sup 2+} or Ca{sup 2+}. Experimental results of TTC indicate that MnO{sub 2} promotes isomerization at the C ring to form iso-TTC and oxidizes the phenolic-diketone and tricarbonylamide groups, leading to insertion of up to 2 O most likely at the C9 and C2 positions. In contrast, reactions of OTC with MnO{sub 2} generate little iso-OTC, but occur mainly at the A ring's dimethylamine group to yield N-demethylated products. CTC yields the most complicated products upon reactions with MnO{sub 2}, encompassing transformation patterns observed with both TTC and OTC. The identified product structures suggest lower antibacterial activity than that of the parent tetracyclines. - Highlights: > Tetracyclines transform rapidly by MnO{sub 2} to yield complicated products. > Isomerized, (hydr)oxygenated and N-demethylated products are formed. > Transformation product structures may suggest lowered antibacterial activity. - The complex transformation pathways of three popular tetracycline antibiotics (tetracycline, oxytetracycline and chlorotetracycline) with MnO{sub 2} under environmental conditions are systematically evaluated and elucidated.

  7. Transformation kinetics and pathways of tetracycline antibiotics with manganese oxide

    International Nuclear Information System (INIS)

    Chen Wanru; Huang, Ching-Hua

    2011-01-01

    Tetracycline antibiotics including tetracycline (TTC), oxytetracycline (OTC) and chlorotetracycline (CTC) undergo rapid transformation to yield various products in the presence of MnO 2 at mild conditions (pH 4-9 and 22 o C). Reaction rates follow the trend of CTC > TTC > OTC, and are affected by pH and complexation of TCs with Mg 2+ or Ca 2+ . Experimental results of TTC indicate that MnO 2 promotes isomerization at the C ring to form iso-TTC and oxidizes the phenolic-diketone and tricarbonylamide groups, leading to insertion of up to 2 O most likely at the C9 and C2 positions. In contrast, reactions of OTC with MnO 2 generate little iso-OTC, but occur mainly at the A ring's dimethylamine group to yield N-demethylated products. CTC yields the most complicated products upon reactions with MnO 2 , encompassing transformation patterns observed with both TTC and OTC. The identified product structures suggest lower antibacterial activity than that of the parent tetracyclines. - Highlights: → Tetracyclines transform rapidly by MnO 2 to yield complicated products. → Isomerized, (hydr)oxygenated and N-demethylated products are formed. → Transformation product structures may suggest lowered antibacterial activity. - The complex transformation pathways of three popular tetracycline antibiotics (tetracycline, oxytetracycline and chlorotetracycline) with MnO 2 under environmental conditions are systematically evaluated and elucidated.

  8. Assessing potential human health hazards and benefits from subtherapeutic antibiotics in the United States: tetracyclines as a case study.

    Science.gov (United States)

    Cox, Louis Anthony Tony; Popken, Douglas A

    2010-03-01

    Many scientists, activists, regulators, and politicians have expressed urgent concern that using antibiotics in food animals selects for resistant strains of bacteria that harm human health and bring nearer a "postantibiotic era" of multidrug resistant "super-bugs." Proposed political solutions, such as the Preservation of Antibiotics for Medical Treatment Act (PAMTA), would ban entire classes of subtherapeutic antibiotics (STAs) now used for disease prevention and growth promotion in food animals. The proposed bans are not driven by formal quantitative risk assessment (QRA), but by a perceived need for immediate action to prevent potential catastrophe. Similar fears led to STA phase-outs in Europe a decade ago. However, QRA and empirical data indicate that continued use of STAs in the United States has not harmed human health, and bans in Europe have not helped human health. The fears motivating PAMTA contrast with QRA estimates of vanishingly small risks. As a case study, examining specific tetracycline uses and resistance patterns suggests that there is no significant human health hazard from continued use of tetracycline in food animals. Simple hypothetical calculations suggest an unobservably small risk (between 0 and 1.75E-11 excess lifetime risk of a tetracycline-resistant infection), based on the long history of tetracycline use in the United States without resistance-related treatment failures. QRAs for other STA uses in food animals also find that human health risks are vanishingly small. Whether such QRA calculations will guide risk management policy for animal antibiotics in the United States remains to be seen.

  9. [Hygienic substantiation of the permissible levels for tetracycline-group antibiotics in food].

    Science.gov (United States)

    Onishchenko, G G; Sheveleva, S A; Khotimchenko, S A

    2012-01-01

    For the purpose of justification of the hygienic standard for tetracycline-group antibiotics in the food production established in the Russian Federation at more rigid level, than maximum and admissible levels (MAL) of the Codex Alimentarius Commission, the analysis of data of literature on negative nature of impact of low concentration of these antibiotics on an organism and the environmental conditions and risk for health has been performed. Inadequacy of the accepted admissible daily dose (ADD) accepted by The Joint FAO/WHO Expert Committee on Food Additives (JECFA) on action on selection of resistant E. coli in intestines, for the wide contingent of consumers in connection with ignoring of obvious factors of uncertainty (gastrointestinal dysbiosis, age and individual variations in the microbiota of people synergy with other antibiotics residues in food and indirect impact on an organism through microflora from the natural habitat (resistance genes, modified causative organisms with altered properties).. By the analysis of information received with the use of modern molecular and genetic methods, the role of Subinhibitory concentrations (sub-MICs) of tetracyclines as biologically active substances, signaling molecules which, without causing obvious negative consequences in a macroorganism, serve as a major factor of regulation of a transcription in microorganisms and activation of a horizontal gene transfer coding resistance, transferred on conjugative transposons of Tn916-Tn1545 family. Reasonable scientific data on a dominating contribution of minor levels of tetracyclines in globalization in the nature of the most adverse transmissive type of the antibiotic resistance interfaced to formation new bacterial pathotypes, as consequences of irrationally high scales of application in agriculture and strengthened impact on microbic ecosystems of live organisms and objects of habitat are presented. For minimization of this mediated risk for health the need of

  10. Introduction of iodine 131 and bromine 82 in antibiotics of tetracycline group

    International Nuclear Information System (INIS)

    Mironov, V.P.; Kudryashov, V.P.; Grushevich, L.E.; Kuz'mina, T.S.

    1983-01-01

    Chloline- and oxytetracycline reactions with iodide-131-and bromide-82-ions in methanol and acetone are studied. It is established that labelled compounds reveal tetracycline (TC) properties in pharmacokinetic experiments on laboratory animals for 20-25 hours after synthesis; the yield of purposeful preparations for radioactive isotopes is 90-95%. Kinetic dependences of iodine-131 and bromine-82-TC yield on acidity and temperature of medium are presented. TC radiation resistance in solutions and in solid state at different temperatures in the range of absorbed doses of 1-10 Mrad is investigated. The possibility of TC radiation sterilization is shown

  11. Multidrug-Resistant Salmonella enterica Serovar Muenchen from Pigs and Humans and Potential Interserovar Transfer of Antimicrobial Resistance

    OpenAIRE

    Gebreyes, Wondwossen A.; Thakur, Siddhartha

    2005-01-01

    Salmonella serovars are important reservoirs of antimicrobial resistance. Recently, we reported on multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium strains among pigs with resistance to ampicillin, kanamycin, streptomycin, sulfamethoxazole, and tetracycline (resistance [R] type AKSSuT) and resistance to amoxicillin-clavulanic acid, ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline (R type AxACSSuT). In the present study, 67 isolates (39 from humans...

  12. Monitoring tetracycline through a solid-state nanopore sensor

    Science.gov (United States)

    Zhang, Yuechuan; Chen, Yanling; Fu, Yongqi; Ying, Cuifeng; Feng, Yanxiao; Huang, Qimeng; Wang, Chao; Pei, De-Sheng; Wang, Deqiang

    2016-06-01

    Antibiotics as emerging environmental contaminants, are widely used in both human and veterinary medicines. A solid-state nanopore sensing method is reported in this article to detect Tetracycline, which is based on Tet-off and Tet-on systems. rtTA (reverse tetracycline-controlled trans-activator) and TRE (Tetracycline Responsive Element) could bind each other under the action of Tetracycline to form one complex. When the complex passes through nanopores with 8 ~ 9 nanometers in diameter, we could detect the concentrations of Tet from 2 ng/mL to 2000 ng/mL. According to the Logistic model, we could define three growth zones of Tetracycline for rtTA and TRE. The slow growth zone is 0-39.5 ng/mL. The rapid growth zone is 39.5-529.7 ng/mL. The saturated zone is > 529.7 ng/mL. Compared to the previous methods, the nanopore sensor could detect and quantify these different kinds of molecule at the single-molecule level.

  13. Tetracycline inducible gene manipulation in serotonergic neurons.

    Directory of Open Access Journals (Sweden)

    Tillmann Weber

    Full Text Available The serotonergic (5-HT neuronal system has important and diverse physiological functions throughout development and adulthood. Its dysregulation during development or later in adulthood has been implicated in many neuropsychiatric disorders. Transgenic animal models designed to study the contribution of serotonergic susceptibility genes to a pathological phenotype should ideally allow to study candidate gene overexpression or gene knockout selectively in serotonergic neurons at any desired time during life. For this purpose, conditional expression systems such as the tet-system are preferable. Here, we generated a transactivator (tTA mouse line (TPH2-tTA that allows temporal and spatial control of tetracycline (Ptet controlled transgene expression as well as gene deletion in 5-HT neurons. The tTA cDNA was inserted into a 196 kb PAC containing a genomic mouse Tph2 fragment (177 kb by homologous recombination in E. coli. For functional analysis of Ptet-controlled transgene expression, TPH2-tTA mice were crossed to a Ptet-regulated lacZ reporter line (Ptet-nLacZ. In adult double-transgenic TPH2-tTA/Ptet-nLacZ mice, TPH2-tTA founder line L62-20 showed strong serotonergic β-galactosidase expression which could be completely suppressed with doxycycline (Dox. Furthermore, Ptet-regulated gene expression could be reversibly activated or inactivated when Dox was either withdrawn or added to the system. For functional analysis of Ptet-controlled, Cre-mediated gene deletion, TPH2-tTA mice (L62-20 were crossed to double transgenic Ptet-Cre/R26R reporter mice to generate TPH2-tTA/Ptet-Cre/R26R mice. Without Dox, 5-HT specific recombination started at E12.5. With permanent Dox administration, Ptet-controlled Cre-mediated recombination was absent. Dox withdrawal either postnatally or during adulthood induced efficient recombination in serotonergic neurons of all raphe nuclei, respectively. In the enteric nervous system, recombination could not be detected. We

  14. Plasmids which make their host bacteria mutable as well as resistant to ultraviolet irradiation

    International Nuclear Information System (INIS)

    Arai, Toshihiko; Ando, Takao

    1980-01-01

    Some of the naturally occurring Iα, I zeta, M, N, O and T group plasmids increase both the mutability and UV resistance of their host bacteria, while group H and S plasmids only increase mutability. This suggests that these two plasmid-mediated repair functions are separable. The two functions have no direct relation to their restriction-modification systems and nitrofuran resistant functions. In addition, the close linking between the restriction-modification genes and these repair function genes was suggested in group N plasmids. (author)

  15. Continuous-flow chemiluminometric determination of some tetracyclines

    International Nuclear Information System (INIS)

    Syropoulos, A.B.; Calokerinos, A.C.

    1991-01-01

    Chemiluminescence is found to be generated by action of lucigenin or hexacyanoferrate(III) on tetracyclines. The reaction with lucigenin exhibits chemiluminescence after alkaline degradation of tetracyclines to the corresponding iso derivatives. The reaction with hexacyanoferrate (III) occurs after acidic degradation of tetracyclines to corresponding anhydro derivatives. The chemiluminescence reaction takes place in alkaline medium, and allows the development of a continuous-flow method for the determination of 1.00-10.0 μgml -1 oxytetracycline and doxycycline. When applied to commercial formulations, the procedure was relatively free from interferences from common excipients. The results obtained for the assay of dosage forms compared well with those obtained by the official methods and demonstrated good accuracy and precision. (author). 32 refs.; 5 figs.; 6 tabs

  16. Continuous-flow chemiluminometric determination of some tetracyclines

    Energy Technology Data Exchange (ETDEWEB)

    Syropoulos, A B; Calokerinos, A C [University of Athens (greece). Laboratory of Analytical Chemistry

    1991-12-24

    Chemiluminescence is found to be generated by action of lucigenin or hexacyanoferrate(III) on tetracyclines. The reaction with lucigenin exhibits chemiluminescence after alkaline degradation of tetracyclines to the corresponding iso derivatives. The reaction with hexacyanoferrate (III) occurs after acidic degradation of tetracyclines to corresponding anhydro derivatives. The chemiluminescence reaction takes place in alkaline medium, and allows the development of a continuous-flow method for the determination of 1.00-10.0 {mu}gml{sup -1} oxytetracycline and doxycycline. When applied to commercial formulations, the procedure was relatively free from interferences from common excipients. The results obtained for the assay of dosage forms compared well with those obtained by the official methods and demonstrated good accuracy and precision. (author). 32 refs.; 5 figs.; 6 tabs.

  17. Two optically active molybdenum disulfide quantum dots as tetracycline sensors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhuosen; Lin, Jintai [School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Gao, Jinwei [Institute for Advanced Materials, Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006 (China); Wang, Qianming, E-mail: qmwang@scnu.edu.cn [Key Laboratory of Theoretical Chemistry of Environment, Ministry of Education, School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); School of Chemistry and Environment, South China Normal University, Guangzhou 510006 (China); Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, 510006 (China)

    2016-08-01

    In this work, we use the hydrothermal method to develop two luminescent MoS{sub 2} quantum dots (QDs) from L-cysteine and glutathione as sulfur precursors. The special blue emissions give rise to an instantaneous determination of tetracycline (TC) through the quenching of its luminescence. The accessibility of the optical materials and recognition mechanism have been extensively studied. This strategy demonstrated that MoS{sub 2} could act as a new platform for anchoring bioactive species or particular functional moieties. - Highlights: • MoS{sub 2} nanostructures with water solubility have been fabricated. • Blue emission has been achieved. • It displays selective detection to tetracyclines in water.

  18. Synthetic tetracycline-inducible regulatory networks: computer-aided design of dynamic phenotypes

    Directory of Open Access Journals (Sweden)

    Kaznessis Yiannis N

    2007-01-01

    Full Text Available Abstract Background Tightly regulated gene networks, precisely controlling the expression of protein molecules, have received considerable interest by the biomedical community due to their promising applications. Among the most well studied inducible transcription systems are the tetracycline regulatory expression systems based on the tetracycline resistance operon of Escherichia coli, Tet-Off (tTA and Tet-On (rtTA. Despite their initial success and improved designs, limitations still persist, such as low inducer sensitivity. Instead of looking at these networks statically, and simply changing or mutating the promoter and operator regions with trial and error, a systematic investigation of the dynamic behavior of the network can result in rational design of regulatory gene expression systems. Sophisticated algorithms can accurately capture the dynamical behavior of gene networks. With computer aided design, we aim to improve the synthesis of regulatory networks and propose new designs that enable tighter control of expression. Results In this paper we engineer novel networks by recombining existing genes or part of genes. We synthesize four novel regulatory networks based on the Tet-Off and Tet-On systems. We model all the known individual biomolecular interactions involved in transcription, translation, regulation and induction. With multiple time-scale stochastic-discrete and stochastic-continuous models we accurately capture the transient and steady state dynamics of these networks. Important biomolecular interactions are identified and the strength of the interactions engineered to satisfy design criteria. A set of clear design rules is developed and appropriate mutants of regulatory proteins and operator sites are proposed. Conclusion The complexity of biomolecular interactions is accurately captured through computer simulations. Computer simulations allow us to look into the molecular level, portray the dynamic behavior of gene regulatory

  19. Fast simultaneous electrochemical detection of tetracycline and fluoxetine in water

    NARCIS (Netherlands)

    Ardelean, Magdalena; Pode, Rodica; Schoonman, J.; Pop, Aniela; Manea, Florica

    2017-01-01

    The electrochemical methods-based protocol for simultaneous detection of tetracycline (TC) from antibiotics class and fluoxetine (FXT) from anti-depressive pharmaceuticals class, which belongs to emerging pollutants from water, was developed in this study using carbon nanofiber-epoxy composite

  20. Tetracycline tooth discolouration in Benin City | Sede | Journal of ...

    African Journals Online (AJOL)

    Journal of Medicine and Biomedical Research ... This retrospective study was conducted to examine the incidence and pattern of tetracycline-related tooth discolouration in patients seen at the restorative dental clinic of ... These patients accounted for 2.2% of the 3750 patients that were seen during the period under review.

  1. 21 CFR 520.2345g - Tetracycline hydrochloride and sodium novobiocin tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride and sodium novobiocin... § 520.2345g Tetracycline hydrochloride and sodium novobiocin tablets. (a) Specifications. Each tablet contains the equivalent of 60 milligrams of tetracycline hydrochloride and 60 milligrams of novobiocin, or...

  2. Imipenem-resistance in Serratia marcescens is mediated by plasmid expression of KPC-2.

    Science.gov (United States)

    Su, W-Q; Zhu, Y-Q; Deng, N-M; Li, L

    2017-04-01

    Imipenem is a broad-spectrum carbapenem antibiotic with applications against severe bacterial infections. Here, we describe the identification of imipenem-resistant Serratia marcescens in our hospital and the role of plasmid-mediated KPC-2 expression in imipenem resistance. We used the modified Hodge test to detect carbapenemase produced in imipenem-resistant strains. His resistance can be transferred to E. coli in co-culture tests, which implicates the plasmid in imipenem resistance. PCR amplification from the plasmid identified two products consistent with KPC-2 of 583 and 1050 bp that were also present in E. coli after co-culture. The restriction pattern for both plasmids was identical, supporting the transfer from the S. marcescens isolate to E. coli. Finally, gene sequencing confirmed KPC-2 in the plasmid. Due to the presence of KPC-2 in the imipenem-resistant S. marcescens, we propose that KPC-2 mediates antibiotic resistance in the S. marcescens isolate.

  3. Outbreak of carbapenem-resistant Providencia rettgeri in a tertiary hospital

    Directory of Open Access Journals (Sweden)

    V S Tshisevhe

    2017-01-01

    Full Text Available The emergence of resistance to multiple antimicrobial agents in pathogenic bacteria is a significant public health threat, as there are limited effective antimicrobial agents for infections caused by multidrug-resistant (MDR bacteria. Several MDR bacteria are now frequently detected. Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics of 4 patients with carbapenem-resistant P. rettgeri were documented. All P. rettgeri isolated in these cases had a carbapenem-resistant antibiogram, with resistance to imipenem, ertapenem and meropenem. These cases could be epidemiologically linked. A multiprong approach, simultaneously targeting antibiotic stewardship, universal precautions and appropriate transmission-based precaution practices, is integral to prevention and control of nosocomial infections.

  4. Fate and transport of veterinary antibiotics, antibiotic-resistant bacteria, and antibiotic resistance gene from fields receiving poultry manure during storm events

    Science.gov (United States)

    Antimicrobials are used in production agriculture to treat disease and promote animal growth, but the presence of antibiotics in the environment raises concern about widespread antibiotic resistance. This study documents the occurrence and transport of tylosin, tetracycline, enterococci resistant to...

  5. Tetracycline-induced renal failure after dental treatment.

    Science.gov (United States)

    Miller, Craig S; McGarity, Gary J

    2009-01-01

    Tetracyclines are broad-spectrum antibiotics used by dental practitioners in the treatment of periodontal disease. They generally are safe in adults. However, caution is advised in patients who have pre-existing kidney disease. A 42-year-old woman with polycystic kidney disease received a prescription for tetracycline (250 milligrams, four times daily) after undergoing tooth extractions. She developed nausea, vomiting and diarrhea within days and end-stage renal disease within two weeks of taking the antibiotic. Hemodialysis was required to stabilize the patient's condition. Use of the Naranjo nomogram demonstrated an association between the two events. This case illustrates the importance of obtaining a thorough medical history and understanding potential adverse drug effects before prescribing a common antibiotic.

  6. Determination of the stability constants of uranium-tetracycline complexes

    International Nuclear Information System (INIS)

    Tarenzi, L.R.; Saiki, M.

    1983-01-01

    Stability constants of complexes formed with tetracycline (TC) and uranium have been determined by solvent extraction technique. The site on the tetracycline molecule at which uranyl ion may be bound has been studied by means of potentiometric titration and spectrophotometric techniques. The complex species with 1:1 and 1:2 for UO 2 : TC ratio have been identified by conductometric titration. Solvent extraction studies have also shown that the complexes are mononuclear of the type UO 2 (TC) sub (n) (n=1,2) and that no hidroxocomplexes or negatively charged complexes have been formed. Stability constant values have been calculated by numerical weighted least square method and by graphical methods of two parameters, of the average number of ligands and of the limiting value. (Author) [pt

  7. Sonocatalytic Degradation of Antibiotics Tetracycline by Mn-Modified Diatomite

    OpenAIRE

    Guo, Yiping; Mi, Xiao; Li, Guoting; Chen, Xi

    2017-01-01

    Mn-modified diatomite was prepared by wet impregnation and subsequent calcinations processes. It was used as catalyst for sonocatalytic degradation of antibiotics tetracycline. Characterizations by scanning electron microscopy and X-ray diffraction pattern showed that the morphology and crystal structure of the modified diatomite were similar to these of raw diatomite. Despite containing very limited amount of Mn oxides, the Mn-modified diatomite showed much higher sonocatalytic activity than...

  8. DNA alterations photosensitized by tetracycline and some of its derivatives

    International Nuclear Information System (INIS)

    Piette, J.; Decuyper, J.; Van de Vorst, A.

    1986-01-01

    Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free radical has been confirmed by electron paramagnetic resonance (EPR) spin trapping experiments using 5,5-dimethyl-1-pyrroline-N-oxide as spin trap. In addition to the EPR signal due to OH radicals trapping another unassigned signal has been detected

  9. Tetracycline Reduces Kidney Damage Induced by Loxosceles Spider Venom

    Directory of Open Access Journals (Sweden)

    Cinthya Kimori Okamoto

    2017-03-01

    Full Text Available Envenomation by Loxosceles spider can result in two clinical manifestations: cutaneous and systemic loxoscelism, the latter of which includes renal failure. Although incidence of renal failure is low, it is the main cause of death, occurring mainly in children. The sphingomyelinase D (SMase D is the main component in Loxosceles spider venom responsible for local and systemic manifestations. This study aimed to investigate the toxicity of L. intermedia venom and SMase D on kidney cells, using both In vitro and in vivo models, and the possible involvement of endogenous metalloproteinases (MMP. Results demonstrated that venom and SMase D are able to cause death of human kidney cells by apoptosis, concomitant with activation and secretion of extracellular matrix metalloproteases, MMP-2 and MMP-9. Furthermore, cell death and MMP synthesis and secretion can be prevented by tetracycline. In a mouse model of systemic loxoscelism, Loxosceles venom-induced kidney failure was observed, which was abrogated by administration of tetracycline. These results indicate that MMPs may play an important role in Loxosceles venom-induced kidney injury and that tetracycline administration may be useful in the treatment of human systemic loxoscelism.

  10. Use of tetracycline as complexing agent in radiochemical separations

    International Nuclear Information System (INIS)

    Saiki, M.; Nastasi, M.J.C.; Lima, F.W.

    1981-01-01

    The use of the antibiotic agent tetracycline (TC) for analytical purposes in solvent extraction procedures is presented. Individual extraction curves for the lanthanides, zinc, scandium, uranium, thorium, neptunium and protactinium were obtained. Separation of those elements from one another, and of uranium from selenium, bromine, antimony, barium, tantalum and tungsten was carried out. In all cases benzyl alcohol was the diluent used to dissolve tetracycline hydrochloride. Sodium chloride was used as supporting electrolyte for the lanthanide separations and sodium perchlorate for the other elements mentioned. Stability or formation constants for the lanthanide complexes as well as for thorium complex with tetracycline were determined by using the methods of average number of ligands, the limiting value (for thorium), the two parameters and the weighted least squares. For the lanthanides, the stability constants of the complexes Ln(TC) 3 go from 9.35+-0.22 for lanthanum up to 10.84+-0.11 for lutetium. For the Th(TC) 4 complex the formation constant is equal to 24.6+-0.3. Radioisotopes of the respective elements were used as tracers for the determinations. (author)

  11. Pharmacodynamic modelling of in vitro activity of tetracycline against a representative, naturally occurring population of porcine Escherichia coli

    DEFF Research Database (Denmark)

    Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

    2015-01-01

    of Escherichia coli representative of those found in the Danish pig population, we compared the growth of 50 randomly selected strains. The observed net growth rates were used to describe the in vitro pharmacodynamic relationship between drug concentration and net growth rate based on E max model with three...... concentrations, and this decline was greater in susceptible strains than resistant strains. The lag phase, defined as the time needed for the strain to reach an OD600 value of 0.01, increased exponentially with increasing tetracycline concentration. The pharmacodynamic parameters confirmed that the [Formula: see...

  12. Kinetics of tetracycline, oxytetracycline, and chlortetracycline adsorption and desorption on two acid soils

    DEFF Research Database (Denmark)

    Fernandez Calviño, David; Bermúdez-Couso, Alipio; Arias-Estévez, Manuel

    2015-01-01

    The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments...... tetracycline > oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline...... > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics...

  13. Subacute neuronopathy in a young man: a possible association with tetracycline treatment

    Directory of Open Access Journals (Sweden)

    Magnus Vrethem

    2011-11-01

    Full Text Available A young man with subacute neuronopathy following tetracycline treatment is described. The symptoms started as a sensory dorsal root affection but by time also involved motor nerves. He developed a severe sensory ataxia with pseudoathetotic movements. Other possible aetiologies were scrutinized and excluded. Tetracycline induced neuronopathy is hitherto not reported in the literature. We propose a possible association between treatment with tetracycline and the development of sensory neuronopathy in this patient.

  14. Multidrug Resistance in Infants and Children

    Directory of Open Access Journals (Sweden)

    Gian Maria Pacifici

    2018-02-01

    Full Text Available Bacterial infections may cause disease and death. Infants and children are often subject to bacterial infections. Antimicrobials kill bacteria protecting the infected patients andreducing the risk of morbidity and mortality caused by bacteria. The antibiotics may lose their antibacterial activity when they become resistant to a bacteria. The resistance to different antibiotics in a bacteria is named multidrug-resistance. Gram-negative bacilli, especially Escherichia coli, Klebsiella, Enterobacter, Salmonella, Shigella, Pseudomonas, Streptococcus, and Haemophilus influenzae type b, may become resistant. Amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, and gentamicin may cause bacterial-resistance. Resistance to bacteria for several pathogens makes complications in the treatment of infections caused by them. Salmonella strains may become resistant to ampicillin, cephalotin, ceftriaxone, gentamicin, amikacin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Shigella strains may become resistant to ampicillin, cotrimoxazole, chloramphenicol, and streptomycin. Multidrug-resistance of Streptococcus pneumoniae may be due to β-lactams, macrolides, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Multidrug-resistance of Pseudomonas aeruginosa may become resistant to β-lactams, chloramphenicol, trimethoprim-sulfamethoxazole, and tetracycline. The antibacterial activity against Haemophilus strains may occur with ampicillin, sulbactam-ampicillin, trimethoprim-sulfamethoxazole, gentamicin, chloramphenicol, and ciprofloxacin. Multidrug-resistance of the Klebsiella species may be due with ampicillin, cefotaxime, cefuroxime, co-amxilav, mezlocillin, chloramphenicol, gentamicin, and ceftazidime. Multidrug-resistance of Escherichia coli may be caused by ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime. Vibrio

  15. Escherichia coli producing CMY-2 β-lactamase in bovine mastitis milk.

    Science.gov (United States)

    Endimiani, Andrea; Bertschy, Isabelle; Perreten, Vincent

    2012-01-01

    An Escherichia coli isolate producing the CMY-2 β-lactamase was found in the milk of a cow with recurrent subclinical mastitis. The isolate was resistant to the antibiotics commonly used for intramammary mastitis treatment, such as penicillins, cephalosporins, β-lactam/β-lactamase inhibitor combinations, aminoglycosides, tetracyclines, and sulfonamides. This is the first report of a plasmid-mediated AmpC-producing Enterobacteriaceae in bovine milk.

  16. Effect of Tetracycline and Vitamin E on Spatial Memory, Learning, and Depression in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Neda Naderi

    2015-12-01

    Full Text Available Background and Objectives: Tetracyclines are antibiotics that are widely used. Tetracycline, easily passes the blood-brain barrier and protects the nervous system due to its specific chemical structure. Vitamin E is one of the fat-soluble vitamins. This vitamin helps prevent the progression of Alzheimer's disease. The purpose of the present study is to investigate the effects of tetracycline and vitamin E on spatial memory, learning, and depression.   Methods: In this experimental study, 21 male Wistar rats were randomly divided into 3 groups of 7 each. The effect of tetracycline and vitamin E on memory, learning, and depression was investigated using 8-arm radial maze and elevated plus maze. Data were analyzed by one-way ANOVA and Tukey's statistical tests. Statistical significance level was considered p<0.05.   Results: After 21 days of treatment, it was shown that tetracycline antibiotic has a significant effect on memory. Also Vitamin E significantly reduced depression and its protective effect decreased the adverse effect of tetracycline. In the treatment group, vitamin E along with tetracycline had a significant effect on memory loss.   Conclusion: The results of the present study indicated that use of vitamin E can reduce depression by its antioxidant and protective effects. Tetracycline also significantly increases memory. Therefore, according to the results, it is suggested that tetracycline be used along with vitamin E to reduce negative effects of the drug.

  17. Rapid colorimetric sensing of tetracycline antibiotics with in situ growth of gold nanoparticles

    International Nuclear Information System (INIS)

    Shen, Li; Chen, Jing; Li, Na; He, Pingli; Li, Zhen

    2014-01-01

    Highlights: • Tetracyclines directly reduce aurate into gold nanoparticles. • Gold nanoparticles showed characteristic plamson absorbance at 526 nm. • Quantitative detection of tetracyclines with the colorimetric assay. • Tetracyclines spiked urine samples can be detected with the assay. - Abstract: A colorimetric assay utilizing the formation of gold nanoparticles was developed to detect tetracycline antibiotics in fluidic samples. Tetracycline antibiotics showed the capability of directly reducing aurate salts into atomic gold which form gold nanoparticles spontaneously under proper conditions. The resulted gold nanoparticles showed characteristic plasmon absorbance at 526 nm, which can be visualized by naked eyes or with a spectrophotometer. UV–vis absorbance of the resulted gold nanoparticles is correlated directly with the concentrations of tetracycline antibiotics in the solution, allowing for quantitative colorimetric detection of tetracycline antibiotics. Reaction conditions, such as pH, temperature, reaction time, and ionic strength were optimized. Sensitivity of the colorimetric assay can be enhanced by the addition of gold nanoparticle seeds, a LOD as low as 20 ng mL −1 can be achieved with the help of seed particles. The colorimetric assay showed minimum interference from ethanol, methanol, urea, glucose, and other antibiotics such as sulfonamides, amino glycosides etc. Validity of the method was also evaluated on urine samples spiked with tetracycline antibiotics. The method provides a broad spectrum detection method for rapid and sensitive detection of reductive substances such as tetracycline antibiotics in liquid and biological samples

  18. Rapid colorimetric sensing of tetracycline antibiotics with in situ growth of gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Li [Logistics School, Beijing Wuzi University, Beijing 101149 (China); Chen, Jing; Li, Na [Logistics School, Beijing Wuzi University, Beijing 101149 (China); He, Pingli [State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing 100094 (China); Li, Zhen [State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193 (China)

    2014-08-11

    Highlights: • Tetracyclines directly reduce aurate into gold nanoparticles. • Gold nanoparticles showed characteristic plamson absorbance at 526 nm. • Quantitative detection of tetracyclines with the colorimetric assay. • Tetracyclines spiked urine samples can be detected with the assay. - Abstract: A colorimetric assay utilizing the formation of gold nanoparticles was developed to detect tetracycline antibiotics in fluidic samples. Tetracycline antibiotics showed the capability of directly reducing aurate salts into atomic gold which form gold nanoparticles spontaneously under proper conditions. The resulted gold nanoparticles showed characteristic plasmon absorbance at 526 nm, which can be visualized by naked eyes or with a spectrophotometer. UV–vis absorbance of the resulted gold nanoparticles is correlated directly with the concentrations of tetracycline antibiotics in the solution, allowing for quantitative colorimetric detection of tetracycline antibiotics. Reaction conditions, such as pH, temperature, reaction time, and ionic strength were optimized. Sensitivity of the colorimetric assay can be enhanced by the addition of gold nanoparticle seeds, a LOD as low as 20 ng mL{sup −1} can be achieved with the help of seed particles. The colorimetric assay showed minimum interference from ethanol, methanol, urea, glucose, and other antibiotics such as sulfonamides, amino glycosides etc. Validity of the method was also evaluated on urine samples spiked with tetracycline antibiotics. The method provides a broad spectrum detection method for rapid and sensitive detection of reductive substances such as tetracycline antibiotics in liquid and biological samples.

  19. Mechanisms of quinolone resistance and implications for human and animal health

    Directory of Open Access Journals (Sweden)

    Velhner Maja

    2010-01-01

    Full Text Available Quinolone antibiotics have been widely used in human and veterinary medicine. This has caused the development of resistance and difficulties in the treatment of complicated bacterial infections in humans. The resistance to quinolones develops due to chromosome mutations and it can also be transferred by plasmids. The target enzyme for quinolones in Gram-negative bacteria is Gyrasa A, while the target enzyme in Grampositive bacteria is mostly topoisomerase IV. Gyrase A consists of two subunits encoded by genes gyrA and gyrB. The function of the enzyme is to introduce negative super coiling in DNA and therefore is essential for the replication of bacteria. Quinolone resistance develops if point mutations at 83 and/or 87 codon are introduced on gyrA. Establishing a minimal inhibitory concentration (MIC to this group of antimicrobials will reveal possible mutations. Recently it was discovered that quinolone resistance is transmittable by plasmid termed PMQR (plasmid mediated quinolone resistance. The target gene marked qnr encodes a pentapeptide repeat family protein. Pentapeptide repeats form sheets, involved in protein-protein interactions. Qnr protein binds to GyrA protecting the enzyme from the inhibitory effect of ciprofloxacin. The distribution of qnr related resistance is higher in humans than in animals. In poultry, however, this type of resistance is present more than in other animals. Plasmid mediated resistance contributes to the faster spread of quinolone resistance. Proper food handling will significantly contribute to decreasing the risk from infection to which people are exposed. In medical and veterinary laboratories antimicrobial resistance monitoring in clinical and environmental isolates is advised. Since correlation between antibiotics application and antimicrobial resistance is often suggested, antimicrobial use must be under strict control of the authorities both in human and in veterinary medicine. .

  20. Collateral damage of flomoxef therapy: in vivo development of porin deficiency and acquisition of blaDHA-1 leading to ertapenem resistance in a clinical isolate of Klebsiella pneumoniae producing CTX-M-3 and SHV-5 beta-lactamases.

    Science.gov (United States)

    Lee, Chen-Hsiang; Chu, Chishih; Liu, Jien-Wei; Chen, Yi-Shung; Chiu, Chiung-Jung; Su, Lin-Hui

    2007-08-01

    The study aimed to characterize the genetic basis of flomoxef and collateral ertapenem resistance in a clinical isolate of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) after flomoxef exposure. Four ESBL-KP isolates (Lkp11-14) were recovered sequentially from four episodes of bacteraemia in an elderly patient. Laboratory investigations included genotyping by PFGE, resistance gene analysis by PCR and sequencing, and outer membrane protein analysis by SDS-PAGE. Plasmid analysis by DNA-DNA hybridization, electroporation and conjugation was also performed. Lkp14 was recovered after 21 days of flomoxef therapy. It demonstrated an indistinguishable PFGE pattern when compared with those produced by Lkp11-13. However, resistance to both flomoxef and ertapenem emerged in Lkp14. Molecular characterization revealed that, in addition to the pre-existing ESBL production (CTX-M-3 and SHV-5) and OmpK35 deficiency found in Lkp11-13, Lkp14 had acquired an extra plasmid-mediated AmpC beta-lactamase gene (blaDHA-1) and failed to express OmpK36, because of insertional inactivation by an insertion sequence IS5. Other resistance mechanisms, such as production of carbapenem-hydrolysing enzymes or expression of chromosomal efflux, were apparently not involved. Conjugational transfer of the plasmid-mediated blaDHA-1 gene into Lkp11 resulted in a significant increase in the MICs of cephamycins and beta-lactamase inhibitors, but not in those of carbapenems. Lkp14 was apparently derived from the previously flomoxef-susceptible isolates, Lkp11-13. After flomoxef exposure, the in vivo acquisition of the plasmid-mediated blaDHA-1 gene has led to flomoxef resistance in Lkp14, and the concomitant depletion of OmpK36 expression has resulted in a collateral effect of ertapenem resistance and diminished susceptibilities to imipenem and meropenem.

  1. Identification of the chelocardin biosynthetic gene cluster from Amycolatopsis sulphurea: a platform for producing novel tetracycline antibiotics.

    Science.gov (United States)

    Lukežič, Tadeja; Lešnik, Urška; Podgoršek, Ajda; Horvat, Jaka; Polak, Tomaž; Šala, Martin; Jenko, Branko; Raspor, Peter; Herron, Paul R; Hunter, Iain S; Petković, Hrvoje

    2013-12-01

    Tetracyclines (TCs) are medically important antibiotics from the polyketide family of natural products. Chelocardin (CHD), produced by Amycolatopsis sulphurea, is a broad-spectrum tetracyclic antibiotic with potent bacteriolytic activity against a number of Gram-positive and Gram-negative multi-resistant pathogens. CHD has an unknown mode of action that is different from TCs. It has some structural features that define it as 'atypical' and, notably, is active against tetracycline-resistant pathogens. Identification and characterization of the chelocardin biosynthetic gene cluster from A. sulphurea revealed 18 putative open reading frames including a type II polyketide synthase. Compared to typical TCs, the chd cluster contains a number of features that relate to its classification as 'atypical': an additional gene for a putative two-component cyclase/aromatase that may be responsible for the different aromatization pattern, a gene for a putative aminotransferase for C-4 with the opposite stereochemistry to TCs and a gene for a putative C-9 methylase that is a unique feature of this biosynthetic cluster within the TCs. Collectively, these enzymes deliver a molecule with different aromatization of ring C that results in an unusual planar structure of the TC backbone. This is a likely contributor to its different mode of action. In addition CHD biosynthesis is primed with acetate, unlike the TCs, which are primed with malonamate, and offers a biosynthetic engineering platform that represents a unique opportunity for efficient generation of novel tetracyclic backbones using combinatorial biosynthesis.

  2. Sonocatalytic Degradation of Antibiotics Tetracycline by Mn-Modified Diatomite

    Directory of Open Access Journals (Sweden)

    Yiping Guo

    2017-01-01

    Full Text Available Mn-modified diatomite was prepared by wet impregnation and subsequent calcinations processes. It was used as catalyst for sonocatalytic degradation of antibiotics tetracycline. Characterizations by scanning electron microscopy and X-ray diffraction pattern showed that the morphology and crystal structure of the modified diatomite were similar to these of raw diatomite. Despite containing very limited amount of Mn oxides, the Mn-modified diatomite showed much higher sonocatalytic activity than the raw diatomite. The increases in both MnSO4 concentration of the wet impregnation solution and the catalyst dosage could enhance the degradation of antibiotics tetracycline significantly. Kapp values for ultrasonication, catalyst adsorption, and both processes combined (0.10 mol/L MnSO4-modified diatomite were 1.22 × 10−4, 0.00193, and 0.00453 min−1, respectively, while the corresponding values of R2 were 0.956, 0.986, and 0.953, respectively. These results demonstrated the significant synergetic effect by combining ultrasonication and catalyst adsorption processes. The presence of isopropanol, KBr, and NaN3 quenched a series of reactive oxygen species sharply, indicating the dominant role of reactive oxygen species in the sonocatalytic process. In contrast, the addition of Fe(II enhanced the degradation due to the generation of more OH∙ radicals in the concurrent Fenton reaction. All the results indicated that Mn-modified diatomite had the great potential for water treatment by sonocatalytic oxidation.

  3. Effect of Tetracycline on Late-stage African trypanosomiasis in Rats ...

    African Journals Online (AJOL)

    Effect of Tetracycline on Late-stage African trypanosomiasis in Rats. T.O. Johnson, J.T. Ekanem. Abstract. The effect of tetracycline on late stage African trypanosomiasis was examined in an in vivo experiment using rats infected with Trypanosoma brucei brucei. Infected rats were treated on the 5th day of infection with ...

  4. Differential Top10 promoter regulation by six tetracycline analogues in plant cells

    Science.gov (United States)

    Love, John; Allen, George C.; Gatz, Christiane; Thompson, William F.; Brown, C. S. (Principal Investigator)

    2002-01-01

    The effects of five tetracycline analogues, anhydrotetracycline, doxycycline, minocycline, oxytetracycline, and tetracycline, on Top10 promoter activity in NT1 tobacco tissue culture cells have been analysed. The concentration that repressed Top10 promoter activity, the level of transgene repression and the kinetics of transgene de-repression were determined for each analogue, and could not be predicted from in vitro binding affinity to the tetracycline repressor or from comparison with animal cells. Doxycycline had the most potent effect on the Top10 promoter and completely inhibited transgene expression at 4 nmol l(-1). Tetracycline was the most versatile of the analogues tested; tetracycline inhibited the Top10 promoter at 10 nmol l(-1) and was easily washed out to restore Top10-driven expression in 12-24 h. A study was also made of the suitability for plant research of a novel tetracycline analogue, GR33076X. In animal cells, GR33076X de-repressed Top10 promoter activity in the presence of inhibitory concentrations of anhydrotetracycline. In NT1, it is shown that GR 33076X can antagonize repression of the Top10 promoter in the presence of tetracycline, but not of anhydrotetracycline or of doxycycline. Different tetracycline analogues can therefore be used to regulate the Top10 promoter in plant cells and this property may be exploited in planning an optimum course of transgene regulation.

  5. 21 CFR 520.2345h - Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Tetracycline hydrochloride, sodium novobiocin, and... ANIMAL DRUGS § 520.2345h Tetracycline hydrochloride, sodium novobiocin, and prednisolone tablets. (a... the first stage of parturition when administered during the last trimester of pregnancy and may...

  6. Tetracyclines Disturb Mitochondrial Function across Eukaryotic Models: A Call for Caution in Biomedical Research

    Directory of Open Access Journals (Sweden)

    Norman Moullan

    2015-03-01

    Full Text Available In recent years, tetracyclines, such as doxycycline, have become broadly used to control gene expression by virtue of the Tet-on/Tet-off systems. However, the wide range of direct effects of tetracycline use has not been fully appreciated. We show here that these antibiotics induce a mitonuclear protein imbalance through their effects on mitochondrial translation, an effect that likely reflects the evolutionary relationship between mitochondria and proteobacteria. Even at low concentrations, tetracyclines induce mitochondrial proteotoxic stress, leading to changes in nuclear gene expression and altered mitochondrial dynamics and function in commonly used cell types, as well as worms, flies, mice, and plants. Given that tetracyclines are so widely applied in research, scientists should be aware of their potentially confounding effects on experimental results. Furthermore, these results caution against extensive use of tetracyclines in livestock due to potential downstream impacts on the environment and human health.

  7. The antimicrobial and antifungal efficacy of tetracycline-integrated gutta-percha

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2008-01-01

    Full Text Available The purpose of this study was in vitro evaluation of the antimicrobial and antifungal efficacy of commercially available gutta-percha containing tetracycline on some potential endodontic pathogens. The test microorganisms were Enterococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus, Porphyromonas endodontalis, and Candida albicans . Tetracycline-integrated gutta-percha (TGP cones, tetracycline disc, and conventional gutta-percha cones of the same size were placed on the inoculated plates. The plates were incubated at 37°C aerobically or anaerobically. Growth inhibition zones on each plate were inspected at 24, 48, and 72 h. Tetracycline disc and TGP cones inhibited all the tested bacterial strains, however the greatest antimicrobial effect was seen on S. aureus. Tetracycline disc and TGP seemed less effective on E. faecalis and P. aeruginosa. However, all tested treatments were unable to affect C. albicans . Based on the results of this study, it seems that TGP offers an antimicrobial advantage over conventional gutta-percha.

  8. [New aspects of safety assessment and food contamination with antibiotics of tetracycline group in the light of harmonization of hygienic standards in Russia and Customs Union with the international standards].

    Science.gov (United States)

    Onishchenko, G G; Sheveleva, S A; Khotimchenko, S A

    2012-01-01

    To address the issue of harmonization of Russian MRLs for tetracycline in food and on the basis of the tasks of preserving the value of hygienic standard for the more restrictive level than similar standards of the Codex Alimentarius Commission in this survey we analyzed the evidences of the negative effects of subingibitory amounts of these antibiotics (lying below the MIC for clinically relevant microorganisms). The inadequacy of the microbiological JECFA ADI and the necessity of using of methodology of analyzing the effects of biological active substances in small doses for assessing the risk of food contamination of tetracycline subingibitory concentrations were demonstrated. Current scientific information on the functions of antibiotics as signaling molecules in the microbial world and the role of tetracycline as a leading factor in the regulation of transcription in microorganisms and activation of the horizontal transfer of resistance genes transferred to the family of conjugative transposons Tn916-Tn1545 also was reviewed in paper. Evidence-based data regarding the basic contribution of subingibitory concentrations of tetracycline in the spread of worst transmissible type of antibiotic resistance and the formation of new pathogens, associated with it, are represented. To reduce the risk of direct adverse effects on microbial ecosystem in the human body and its habitat, and to minimize the indirect risk of new infections, the necessity of saving the current Russian level residues of tetracycline (< or = 0.01 mg/kg of product), which is low by contrast to the Codex MRLs (< or = 0.1-1.2 mg/kg), was proved. Tetracycline concentrations in food, regulated in Russian Federation, below 0.1 MIC for clinically significant microorganisms which aren't capable to initiation of the above described negative changes.

  9. Use of tetracycline as complexing agent in analytical chemistry

    International Nuclear Information System (INIS)

    Nastasi, M.J.C.; Saiki, M.; Lima, F.W.

    1977-01-01

    The behavior of tetracyline as complexing agent in solvent extraction studies is presented. The extraction curves for the lanthanide elements, scandium, thorium, uranium and neptunium, are determined for the extraction system benzyl alcohol-tetracycline, as well as the acid and extractant dependences of extraction of the lanthanide elements. Separation of neptunium from uranium is formed by carrying out the extraction experiment at a proper pH value. Use is made of masking agents namely, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), in order to obtain separations of uranium from scadium and lanthanides as well as of uranium and thorium, respectively. The extraction experiments are carried out by using radioisotopes of each element, except for uranium in which case the determinations are by using epithermal neutron activation analysis [pt

  10. Effect of radiation on tyrosine and tetracycline in poultry meat

    International Nuclear Information System (INIS)

    Vachin, I.; Pavlov, A.; Lashev, L.

    1994-01-01

    The effect of gamma rays on tissue level changes of unbound tyrosine and tetracycline was examined in comparative trials with broiler chicken meat. White meat and dark meat samples were taken from the killed chicken and were frozen at -18 o C. The three experimental groups were gamma irradiated with doses of 1.0, 1.5 and 2 kGy. The contents of the unbound antibiotics were microbiologically tested on 24th hour and 45th day after irradiation using Bacillus subtilis ATCC 6633, respectively Bac. mycoides HB 2 as test organisms. It was found that on 25th hour after irradiation both antibiotics were not significantly changed compared to the controls. After 45 days of storage a tendency towards decreasing the antibiotic concentrations in both the white and dark meat had been detected. (author)

  11. γ-radiation induced tetracycline removal in an aqueous solution

    International Nuclear Information System (INIS)

    Zhou Fei; Guo Zhaobing; Zhang Chaozhi; Lin Mingyue; Wu Menglong; Zhao Yongfu

    2012-01-01

    Degradation effect of tetracycline (TC) by γ-radiation was investigated in an aqueous solution. The effects of initial concentrations of TC, pH values, combining with H 2 O 2 or CH 3 OH on degradation of TC were studied. Results showed that TC can be effectively degradated by γ-irradiation in an aqueous solution. Degradation of TC could be remarkably improved both in acid solution and alkaline solution, especially when pH value was 9.0. In addition, H 2 O 2 could gently promote degradation of TC induced by γ-radiation. While, CH 3 OH markedly restrained degradation of TC induced by γ-radiation. The degradation mechanism of TC was supposed by results of quantum chemical calculations and LC-MS. Results proved that degradation of TC induced by γ-radiation was mainly ascribed to · OH oxidation. (authors)

  12. Determination of stability constants of lanthanide complexes with tetracycline

    International Nuclear Information System (INIS)

    Saiki, Mitiko

    1975-01-01

    The stability constants of complexes compounds formed with tetracycline and lanthanides elements were determined for all lanthanides except promethium. The experimental procedure used was solvent extraction of the lanthanides labelled with their radioactive isotopes. It was shown that the formed complexes are mononuclear and that no hydroxo complexes or negatively charged complexes are formed in the experimental conditions of this work. Four methods of calculation were used for all complexes studied: the method of the average number of ligands, the method of limiting value, the method of two parameters and the method of weighted least squares. A comparison was made of the graphical methods with the method of least squares, showing the convenience of preceding least squares calculation by the graphical methods, in order to verify eventual mistakes of numerical data. It was shown the advantage of using radioisotopes of the elements for such a study, specially if the solvent extraction technique is used to-get the experimental data. (author)

  13. Potential for tumor therapy with tritiated tetracycline. Summary evaluation

    International Nuclear Information System (INIS)

    Davis, R.C.; Wood, P.; Wood, L.L.; Mendelsohn, M.L.

    1976-01-01

    Reports of tetracycline accumulation in human and animal tumors have led a number of investigators to postulate that this drug, if radio-labeled, might have potential as a therapeutic or diagnostic agent. This paper describes attempts to investigate this potential for tritiated tetracycling. The therapeutic studies demonstrated that while a significant reduction in the growth rates of transplanted tumors could be obtained by the administration of heavy doses of TTC relative to uninjected controls, similar reductions were observed in the growth rates of tumors in animals receiving unlabeled TC. In the localization studies in rodents, the concentrations of TTC in normal tissues and tumors were compared and were correlated with the corresponding concentrations of 14 C-thymidine, a measure of proliferative activity

  14. Ultrasensitive chemiluminescence of tetracyclines in the presence of MCLA

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Wangsheng; Zhu, Chenyao [School of Public Health, Nanchang University, Nanchang 330006 (China); Liu, Hongcheng [Institute of Quality Standard and Testing Technology, Yunnan Academy of Agriculture Science, 650223 Kunming (China); Liu, Jing; Cai, Hongping [School of Public Health, Nanchang University, Nanchang 330006 (China); Cheng, Xianglei, E-mail: chengxlsd@163.com [School of Public Health, Nanchang University, Nanchang 330006 (China); Wei, Lijun, E-mail: weilj7681@163.com [School of Public Health, Nanchang University, Nanchang 330006 (China)

    2017-06-15

    In this article, five tetracyclines (TCs) showed ultrasensitive chemiluminescence (CL) based on the novel CL system of methoxylated Cypridina luciferin analogues (MCLA) and Ce(IV). It was found that the CL intensity of MCLA-Ce(IV) system was enhanced 30 times by adding 10 pmol chlortetracycline. Mechanisms of MCLA-Ce(IV)-TCs were investigated by CL spectra, radical scavengers and UV spectra. The results indicated that singlet oxygen, resulting from the reaction between Ce(IV) and TCs, was involved in the enhancement of CL phenomenon. This CL system coupling with flow injection analysis was developed for the determination of five common TCs. Linear ranged from 100 fmol to 20 pmol (r>0.999) with limit of detection of 20 to 50 fmol (S/N=3). The sensitivity of the present method is comparable to that of UPLC-MS/MS detection for TCs.

  15. Primary Antibiotic Resistance of Helicobacter pylori in China.

    Science.gov (United States)

    Hu, Yi; Zhu, Yin; Lu, Nong-Hua

    2017-05-01

    Antibiotic resistance is the most important factor leading to the failure of eradication regimens; thus, it is important to obtain regional antibiotic resistance information. This review focuses on the prevalence of Helicobacter pylori primary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone in China. We searched the PubMed, EMBASE, the China National Knowledge Infrastructure, and Chinese Biomedical databases from the earliest date of each database to October 2016. The search terms included the following: H. pylori, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and furazolidone) resistance with or without China or different regions of China. The data analysis was performed using MedCalc 15.2.2. Each article was weighted according to the number of isolated H. pylori strains. A pooled proportion analysis was performed. Twenty-three studies (14 studies in English and 9 in Chinese) were included in this review. A total of 6274, 6418, 3921, 5468, 2802, and 275 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone, respectively. Overall, the primary resistance rates of clarithromycin, metronidazole, levofloxacin, amoxicillin, tetracycline, and furazolidone were 28.9, 63.8, 28.0, 3.1, 3.9, and 1.7%, respectively. In China, the prevalence of H. pylori primary resistance to clarithromycin, metronidazole, and levofloxacin was high and increased over time, whereas the resistance rates to amoxicillin, tetracycline, and furazolidone were low and stable over time.

  16. Comparison of two modified coal ash ferric-carbon micro-electrolysis ceramic media for pretreatment of tetracycline wastewater.

    Science.gov (United States)

    Yang, Kunlun; Jin, Yang; Yue, Qinyan; Zhao, Pin; Gao, Yuan; Wu, Suqing; Gao, Baoyu

    2017-05-01

    Application of modified sintering ferric-carbon ceramics (SFC) and sintering-free ferric-carbon ceramics (SFFC) based on coal ash and scrap iron for pretreatment of tetracycline (TET) wastewater was investigated in this article. Physical property, morphological character, toxic metal leaching content, and crystal component were studied to explore the application possibility of novel ceramics in micro-electrolysis reactors. The influences of operating conditions including influent pH, hydraulic retention time (HRT), and air-water ratio (A/W) on the removal of tetracycline were studied. The results showed that SFC and SFFC were suitable for application in micro-electrolysis reactors. The optimum conditions of SFC reactor were pH of 3, HRT of 7 h, and A/W of 10. For SFFC reactor, the optimum conditions were pH of 2, HRT of 7 h, and A/W of 15. In general, the TET removal efficiency of SFC reactor was better than that of SFFC reactor. However, the harden resistance of SFFC was better than that of SFC. Furthermore, the biodegradability of TET wastewater was improved greatly after micro-electrolysis pretreatment for both SFC and SFFC reactors.

  17. Immobilization of tetracyclines in manure and manure-amended soils using aluminum-based drinking water treatment residuals.

    Science.gov (United States)

    Punamiya, Pravin; Sarkar, Dibyendu; Rakshit, Sudipta; Elzinga, Evert J; Datta, Rupali

    2016-02-01

    Veterinary antibiotics (VAs) are emerging contaminants of concern in the environment, mainly due to the potential for development of antibiotic-resistant bacteria and effect on microbiota that could interfere with crucial ecosystem functions such as nutrient cycling and decomposition. High levels of VAs such as tetracyclines (TCs) have been reported in agricultural soils amended with manure, which also has the potential to cause surface and groundwater contamination. Several recent studies have focused on developing methods to immobilize VAs such as composting with straw, hardwood chips, commercial biochar, aeration, mixing, heat treatment, etc. The major shortcomings of these methods include high cost and limited effectiveness. In the current study, we assessed the effectiveness of aluminum-based drinking water treatment residuals (Al-WTR) as a "green" sorbent to immobilize TCs in manure and manure-applied soils with varying physicochemical properties by laboratory incubation study. Results show that Al-WTR is very effective in immobilizing tetracycline (TTC) and oxytetracycline (OTC). The presence of phosphate resulted in significant (p < 0.01) decrease in TTC/OTC sorption by Al-WTR, but the presence of sulfate did not. attenuated total reflection (ATR)-FTIR spectroscopy indicate that TTC and OTC likely forming surface complexes via inner-sphere-type bonds in soils, manure, and manure-applied soils amended with Al-WTR.

  18. Simulation of the rate of transfer of antibiotic resistance between Escherichia coli strains cultured under well controlled environmental conditions

    NARCIS (Netherlands)

    Smelt, J.P.; Hoefsloot, H.C.; de Koster, C.G.; Schuurmans, J.M.; ter Kuile, B.H.; Brul, S.

    2015-01-01

    It was demonstrated that the tetracycline resistance plasmid in Escherichia coli resembling K-12 23:06 containing the E. coli plasmid DM0133 could be transferred to tetracycline sensitive E. coli K-12 MG1655 YFP. The sensitive recipient strain has a slight metabolic advantage in continuous

  19. HPLC method validation for modernization of the tetracycline hydrochloride capsule USP monograph

    Directory of Open Access Journals (Sweden)

    Emad M. Hussien

    2014-12-01

    Full Text Available This paper is a continuation to our previous work aiming at development and validation of a reversed-phase HPLC for modernization of tetracycline-related USP monographs and the USP general chapter . Previous results showed that the method is accurate and precise for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline impurity in the drug substance and oral suspension monographs. The aim of the current paper is to examine the feasibility of the method for modernization of USP tetracycline hydrochloride capsule monograph. Specificity, linearity, accuracy and precision were examined for tetracycline hydrochloride assay and 4-epianhydrotetracycline limit. The method was linear in the concentration range from 80% to 160% (r>0.9998 of the assay concentration (0.1 mg/mL for tetracycline hydrochloride and from 50% to 150% (r>0.997 of the acceptance criteria specified in tetracycline hydrochloride capsule monograph for 4-epianhydrotetracycline (NMT 3.0%. The recovery at three concentration levels for tetracycline hydrochloride assay was between 99% and 101% and the RSD from six preparations at the concentration 0.1 mg/mL is less than 0.6%. The recovery for 4-epianhydrotetracycline limit procedure over the concentration range from 50% to 150% is between 96% and 102% with RSD less than 5%. The results met the specified acceptance criteria.

  20. Effective Degradation of Aqueous Tetracycline Using a Nano-TiO2/Carbon Electrocatalytic Membrane

    Directory of Open Access Journals (Sweden)

    Zhimeng Liu

    2016-05-01

    Full Text Available In this work, an electrocatalytic membrane was prepared to degrade aqueous tetracycline (TC using a carbon membrane coated with nano-TiO2 via a sol-gel process. SEM, XRD, EDS, and XPS were used to characterize the composition and structure of the electrocatalytic membrane. The effect of operating conditions on the removal rate of tetracycline was investigated systematically. The results show that the chemical oxygen demand (COD removal rate increased with increasing residence time while it decreased with increasing the initial concentration of tetracycline. Moreover, pH had little effect on the removal of tetracycline, and the electrocatalytic membrane could effectively remove tetracycline with initial concentration of 50 mg·L−1 (pH, 3.8–9.6. The 100% tetracycline and 87.8% COD removal rate could be achieved under the following operating conditions: tetracycline concentration of 50 mg·L−1, current density of 1 mA·cm−2, temperature of 25 °C, and residence time of 4.4 min. This study provides a new and feasible method for removing antibiotics in water with the synergistic effect of electrocatalytic oxidation and membrane separation. It is evident that there will be a broad market for the application of electrocatalytic membrane in the field of antibiotic wastewater treatment.

  1. Degradation of tetracycline in aqueous media by ozonation in an internal loop-lift reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yan [Department of Environmental Engineering, Wuhan University, P.O. Box C319, Luoyu Road 129, Wuhan 430079 (China); Zhang Hui, E-mail: eeng@whu.edu.cn [Department of Environmental Engineering, Wuhan University, P.O. Box C319, Luoyu Road 129, Wuhan 430079 (China); Zhang Jianhua; Lu Chen; Huang Qianqian; Wu Jie; Liu Fang [Department of Environmental Engineering, Wuhan University, P.O. Box C319, Luoyu Road 129, Wuhan 430079 (China)

    2011-08-15

    The degradation of tetracycline by ozone was investigated in this paper. In the laboratory scale experiments, the effect of major parameters, including pH, gas flow rate, gaseous ozone concentration, hydrogen peroxide concentration and hydroxyl radical scavenger (tert-butyl alcohol) on the degradation of tetracycline was studied. A pseudo-first order kinetic model was used to simulate the experimental results. The results indicated that the tetracycline degradation rate increased with pH, gaseous ozone concentration and gas flow rate. The addition of hydrogen peroxide or hydroxyl radical scavenger had little effect on tetracycline removal, indicating that the direct oxidation of tetracycline by ozone was dominant process and the radical contribution to the tetracycline oxidation could be neglected. The main intermediates were separated and identified as well as the simple degradation pathway of tetracycline was proposed. The COD removal reached to 35% after 90 min reaction. The acute toxicity experiments illustrated that the Daphnia magna mortality reached the maximum after 25 min ozonation and then decreased to zero after 90 min ozonation.

  2. Slow release of tetracycline from a mucoadhesive complex with sucralfate for eradication of Helicobacter pylori.

    Science.gov (United States)

    Higo, Shoichi; Takeuchi, Hirofumi; Yamamoto, Hiromitsu; Hino, Tomoaki; Kawashima, Yoshiaki

    2008-10-01

    Treatment composed of a gastric mucoadhesive antibiotic with slow release drug delivery is expected to be effective for the eradication of Helicobacter pylori (H. pylori). In this study, we evaluated the slow release property of the tetracycline-sucralfate acidic complex. Tetracycline was the antibiotic selected because of its complexation capacity with sucralfate. Sustained release was tested using two different dissolution test methods: paddle and flow-through cell. The adhesive paste formed from the acidic complex displayed a longer sustained release profile of tetracycline using flow-through cell method. The milder conditions of the flow-through cell method better mimicked the fasted state of the stomach, suggesting that the oral administration with fasting is appropriate for the acidic complex. Furthermore, the paste formation protected the tetracycline from decomposition under an acidic condition, which apparently contributes to long-term release. Change in the zeta potential of the acidic complex particles was helpful in clarifying the release mechanisms of the tetracycline. The data indicated that the immediate release of tetracycline in the early stage of the test was indispensable to the subsequent paste formation that enables slow release. If administrated orally with fasting, the acidic complex rapidly adheres to the gastric mucosa and sustains long-term release of the tetracycline to the gastric lumen or mucus layer. This antibiotic delivery mechanism, which requires only a minimum dosage, may be effective for efficient eradication of H. pylori.

  3. Using data on resistance prevalence per sample in the surveillance of antimicrobial resistance

    DEFF Research Database (Denmark)

    Vieira, Antonio; Shuyu, Wu; Jensen, Lars Bogø

    2008-01-01

    Objectives: In most existing antimicrobial resistance monitoring programmes, one single bacterial colony from each collected sample is susceptibility tested against a panel of antimicrobials. Detecting the proportion of colonies resistant to different antimicrobials in each sample can provide...... quantitative data on antimicrobial resistance (resistance prevalence per sample). Methods: In this study, a total of 98 faecal samples from slaughter pigs were tested for tetracycline and sulphonamide resistance in Escherichia coli using the single colony method, and these results were compared...... with the results obtained using the resistance prevalence per sample method. Results: The results obtained by the resistance prevalence per sample method showed a lower occurrence of resistance. Tetracycline resistance in E. coli was found in 36.7% of the samples using the single colony method, while the mean...

  4. Enhancement of plasmid-mediated stable gene expression by ...

    African Journals Online (AJOL)

    ARL

    2012-06-12

    Jun 12, 2012 ... production and faithful translation and processing of proteins (Baldi et al., ..... deeper understanding of the interaction of cellular factors and regulatory DNA .... mediated transgene expression in the rat brain. Gene Ther., 7: ...

  5. Contribution to the study of calcium metabolism in rats treated with tetracycline

    International Nuclear Information System (INIS)

    Goncalves, M.R.B.

    1980-01-01

    The tetracycline is one of the most used antibiotics. The interferences in the rats calcium metabolism were studied. Sixteen rats, R dutch type were treated with a 1 mg/100 g of corporal weight, of tetracycline twice a day, for 23 days. In the twentieth day of the treatment, a dose of Calcium 45 was administrated to verify thhe decay curve of the radionuclide plasmatic concentration. A control group of 16 rats was studied to compare the results. A significative decrease of the calcemy and of bone reabsorption in the group treated with tetracycline were observed. (L.M.J.)

  6. A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk

    Directory of Open Access Journals (Sweden)

    Sagar Dhakal

    2018-02-01

    Full Text Available Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm−1 in water-tetracycline solutions and 1322 and 1621 cm−1 (shifted from 1317 and 1632 cm−1, respectively in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm−1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

  7. A Simple Surface-Enhanced Raman Spectroscopic Method for on-Site Screening of Tetracycline Residue in Whole Milk.

    Science.gov (United States)

    Dhakal, Sagar; Chao, Kuanglin; Huang, Qing; Kim, Moon; Schmidt, Walter; Qin, Jianwei; Broadhurst, C Leigh

    2018-02-01

    Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS) method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm) and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm -1 in water-tetracycline solutions and 1322 and 1621 cm -1 (shifted from 1317 and 1632 cm -1 , respectively) in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm -1 were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.

  8. Evaluation of degradation of antibiotic tetracycline in pig manure by electron beam irradiation.

    Science.gov (United States)

    Cho, Jae-Young

    2010-04-01

    This study was carried out to evaluate the degradation efficiency and intermediate products of the tetracycline from artificially contaminated pig manure using of electron beam irradiation as a function of the absorbed dose. The degradation efficiency of tetracycline was 42.77% at 1 kGy, 64.20% at 3 kGy, 77.83% at 5 kGy, and 90.50% at 10 kGy. The initial concentration of tetracycline (300 mg kg(-1)) in pig manure decreased significantly to 24.2 +/- 5.3 mg kg(-1) after electron beam irradiation at 10 kGy. The radiolytic degradation products of tetracycline were 1,4-benzenedicarboxylic acid, hexadecanoic acid, 9-octadecenamide, 11-octadecenamide, and octadecanoic acid.

  9. Biogas generation in anaerobic wastewater treatment under tetracycline antibiotic pressure

    Science.gov (United States)

    Lu, Meiqing; Niu, Xiaojun; Liu, Wei; Zhang, Jun; Wang, Jie; Yang, Jia; Wang, Wenqi; Yang, Zhiquan

    2016-01-01

    The effect of tetracycline (TC) antibiotic on biogas generation in anaerobic wastewater treatment was studied. A lab-scale Anaerobic Baffled Reactor (ABR) with three compartments was used. The reactor was operated with synthetic wastewater in the absence of TC and in the presence of 250 μg/L TC for 90 days, respectively. The removal rate of TC, volatile fatty acids (VFAs), biogas compositions (hydrogen (H2), methane (CH4), carbon dioxide (CO2)), and total biogas production in each compartment were monitored in the two operational conditions. Results showed that the removal rate of TC was 14.97–67.97% in the reactor. The presence of TC had a large negative effect on CH4 and CO2 generation, but appeared to have a positive effect on H2 production and VFAs accumulation. This response indicated that the methanogenesis process was sensitive to TC presence, but the acidogenesis process was insensitive. This suggested that the presence of TC had less influence on the degradation of organic matter but had a strong influence on biogas generation. Additionally, the decrease of CH4 and CO2 generation and the increase of H2 and VFAs accumulation suggest a promising strategy to help alleviate global warming and improve resource recovery in an environmentally friendly approach. PMID:27341657

  10. Transfer and persistence of a multi-drug resistance plasmid in situ of the infant gut microbiota in the absence of antibiotic treatment

    DEFF Research Database (Denmark)

    Gumpert, Heidi; Kubicek-Sutherland, Jessica Z.; Porse, Andreas

    2017-01-01

    lineage was maintained for months, demonstrating that antibiotic resistance genes can disseminate and persist in the gut microbiome; even in absence of antibiotic selection. Furthermore, through in vivo competition assays, we suggest that the resistant transconjugant can persist through a fitness......The microbial ecosystem residing in the human gut is believed to play an important role in horizontal exchange of virulence and antibiotic resistance genes that threatens human health. While the diversity of gut-microorganisms and their genetic content has been studied extensively, high...... infections, as well as the loss and acquisition of plasmids in these lineages during their colonization of the human gut. In particular, we captured the exchange of multidrug resistance genes, and identified a clinically relevant conjugative plasmid mediating the transfer. This resistant transconjugant...

  11. The culturable soil antibiotic resistome: a community of multi-drug resistant bacteria.

    Science.gov (United States)

    Walsh, Fiona; Duffy, Brion

    2013-01-01

    Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes. We have identified and characterized multi-drug resistance (MDR) mechanisms in the culturable soil antibiotic resistome and linked the resistance profiles to bacterial species. We isolated 412 antibiotic resistant bacteria from agricultural, urban and pristine soils. All isolates were multi-drug resistant, of which greater than 80% were resistant to 16-23 antibiotics, comprising almost all classes of antibiotic. The mobile resistance genes investigated, (ESBL, bla NDM-1, and plasmid mediated quinolone resistance (PMQR) resistance genes) were not responsible for the respective resistance phenotypes nor were they present in the extracted soil DNA. Efflux was demonstrated to play an important role in MDR and many resistance phenotypes. Clinically relevant Burkholderia species are intrinsically resistant to ciprofloxacin but the soil Burkholderia species were not intrinsically resistant to ciprofloxacin. Using a phenotypic enzyme assay we identified the antibiotic specific inactivation of trimethoprim in 21 bacteria from different soils. The results of this study identified the importance of the efflux mechanism in the soil resistome and variations between the intrinsic resistance profiles of clinical and soil bacteria of the same family.

  12. The culturable soil antibiotic resistome: a community of multi-drug resistant bacteria.

    Directory of Open Access Journals (Sweden)

    Fiona Walsh

    Full Text Available Understanding the soil bacterial resistome is essential to understanding the evolution and development of antibiotic resistance, and its spread between species and biomes. We have identified and characterized multi-drug resistance (MDR mechanisms in the culturable soil antibiotic resistome and linked the resistance profiles to bacterial species. We isolated 412 antibiotic resistant bacteria from agricultural, urban and pristine soils. All isolates were multi-drug resistant, of which greater than 80% were resistant to 16-23 antibiotics, comprising almost all classes of antibiotic. The mobile resistance genes investigated, (ESBL, bla NDM-1, and plasmid mediated quinolone resistance (PMQR resistance genes were not responsible for the respective resistance phenotypes nor were they present in the extracted soil DNA. Efflux was demonstrated to play an important role in MDR and many resistance phenotypes. Clinically relevant Burkholderia species are intrinsically resistant to ciprofloxacin but the soil Burkholderia species were not intrinsically resistant to ciprofloxacin. Using a phenotypic enzyme assay we identified the antibiotic specific inactivation of trimethoprim in 21 bacteria from different soils. The results of this study identified the importance of the efflux mechanism in the soil resistome and variations between the intrinsic resistance profiles of clinical and soil bacteria of the same family.

  13. Effect of Cl substituent in the aromatic tetracycline ring on its reactivity with solvated electrons

    Energy Technology Data Exchange (ETDEWEB)

    Dziegielewski, J O; Glowacki, P [Universytet Slaski, Katowice (Poland). Inst. Chemii; Goracy, J; Orlowska-Dudek, D; Sloma, E [Wroclaw Univ. (Poland) Inst. Chemii

    1984-09-18

    Decomposition yields of tetracycline hydrochloride (TC.HCl) and chlorotetracycline hydrochloride (ClTC.HCl) in methanol solution saturated with Ar or N/sub 2/O were determined. Rate constants of the reaction esub(s)/sup -/ with some antibiotics were obtained. It was demonstrated by /sup 1/H NMR that the radical formed by degradation of 7-C-Cl group is recombined with the H atoms leading to ClTC.HCl being converted into tetracycline hydrochloride (TC.HCl).

  14. Microplastics play a minor role in tetracycline sorption in the presence of dissolved organic matter.

    Science.gov (United States)

    Xu, Baile; Liu, Fei; Brookes, Philip C; Xu, Jianming

    2018-05-02

    Microplastics have a great potential to sorb organic pollutants from the adjacent environment. In this study, the sorption of tetracycline, a polar and ionizable antibiotic, on three types of microplastics (polyethylene (PE), polypropylene (PP) and polystyrene (PS)) were investigated in batch sorption experiments. The sorption isotherms were well fitted by the Langmuir model, indicating that not only hydrophobic interactions but also other interactions (e.g. electrostatic interactions) played important roles in the sorption process. PS had the maximum sorption capacity, following the order PS > PP > PE, which can be attributed to polar interactions and π-π interactions. The sorption of tetracycline on microplastics was significantly influenced by pH, with sorption capacity increasing gradually, peaking at pH 6.0 and then decreasing, likely due to the influence of tetracycline speciation with the change of pH. Fulvic acid was selected as representative dissolved organic matter (DOM) to examine the effect on sorption. The increasing concentration of fulvic acid inhibited the sorption of tetracycline on three microplastics, decreasing them by more than 90% at the fulvic acid concentration of 20 mg/L, which implied a greater affinity of tetracycline to fulvic acid than to microplastics. Increasing salinity from 0.05 to 3.5% had negligible effects on the sorption of tetracycline on the three microplastics. Our results highlight the importance of pH and DOM on the sorption of tetracycline on microplastics, and suggest the relatively minor role of microplastics in the fate and transport of tetracycline in the aquatic environment in the presence of DOM. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Changes in weight and body fat after use of tetracycline and Lactobacillus gasseri in rats

    OpenAIRE

    Jorge José Marciano; Fernando de Sá Del Fiol; Alessandra Cristina Marciano Tardelli Ferreira; Maria Cláudia Marques; Luciane Lopes Santana

    2017-01-01

    ABSTRACT Recent studies have shown a role of intestinal microbiota in obesity. The consumption of antibiotics in the last 70 years has led to changes in intestinal microbiota, which has led to weight gain and body fat accumulation. To evaluate the possibility of weight gain induced by antibiotics and the possible protective effect of probiotics, we divided 45 animals (Rattus norvegicus) into groups and administered the following treatments over two weeks: tetracycline, tetracycline + Lactobac...

  16. Effects of UV light disinfection on antibiotic-resistant coliforms in wastewater effluents

    International Nuclear Information System (INIS)

    Meckes, M.C.

    1982-01-01

    Total coliforms and total coliforms resistant to streptomycin, tetracycline, or chloramphenicol were isolated from filtered activated sludge effluents before and after UV light irradiation. Although the UV irradiation effectively disinfected the wastewater effluent, the percentage of the total surviving coliform population resistant to tetracycline or chloramphenicol was significantly higher than the percentage of the total coliform population resistant to those antibiotics before UV irradiation. This finding was attributed to the mechanism of R-factor mediated resistance to tetracycline. No significant difference was noted for the percentage of the surviving total coliform population resistant to streptomycin before or after UV irradiation. Multiple drug resistant to patterns of 300 total coliform isolates revealed that 82% were resistant to two or more antibiotics. Furthermore, 46% of these isolates were capable of transferring antibiotic resistance to a sensitive strain of Escherichia coli

  17. Biotransformation of tetracycline by a novel bacterial strain Stenotrophomonas maltophilia DT1.

    Science.gov (United States)

    Leng, Yifei; Bao, Jianguo; Chang, Gaofeng; Zheng, Han; Li, Xingxing; Du, Jiangkun; Snow, Daniel; Li, Xu

    2016-11-15

    Although several abiotic processes have been reported that can transform antibiotics, little is known about whether and how microbiological processes may degrade antibiotics in the environment. This work isolated one tetracycline degrading bacterial strain, Stenotrophomonas maltophilia strain DT1, and characterized the biotransformation of tetracycline by DT1 under various environmental conditions. The biotransformation rate was the highest when the initial pH was 9 and the reaction temperature was at 30°C, and can be described using the Michaelis-Menten model under different initial tetracycline concentrations. When additional substrate was present, the substrate that caused increased biomass resulted in a decreased biotransformation rate of tetracycline. According to disk diffusion tests, the biotransformation products of tetracycline had lower antibiotic potency than the parent compound. Six possible biotransformation products were identified, and a potential biotransformation pathway was proposed that included sequential removal of N-methyl, carbonyl, and amine function groups. Results from this study can lead to better estimation of the fate and transport of antibiotics in the environment and has the potential to be utilized in designing engineering processes to remove tetracycline from water and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Electronic-property dependent interactions between tetracycline and graphene nanomaterials in aqueous solution.

    Science.gov (United States)

    He, Lin; Liu, Fei-Fei; Zhao, Mengyao; Qi, Zhen; Sun, Xuefei; Afzal, Muhammad Zaheer; Sun, Xiaomin; Li, Yanhui; Hao, Jingcheng; Wang, Shuguang

    2018-04-01

    Understanding the interactions between graphene nanomaterials (GNMs) and antibiotics in aqueous solution is critical to both the engineering applications of GNMs and the assessment of their potential impact on the fate and transport of antibiotics in the aquatic environment. In this study, adsorption of one common antibiotic, tetracycline, by graphene oxide (GO) and reduced graphene oxide (RGO) was examined with multi-walled carbon nanotubes (MWCNTs) and graphite as comparison. The results showed that the tetracycline adsorption capacity by the four selected carbonaceous materials on the unit mass basis followed an order of GO>RGO>MWCNTs>graphite. Upon normalization by surface area, graphite, RGO and MWCNTs had almost the same high tetracycline adsorption affinity while GO exhibited the lowest. We proposed π-electron-property dependent interaction mechanisms to explain the observed different adsorption behaviors. Density functional theory (DFT) calculations suggested that the oxygen-containing functional groups on GO surface reduced its π-electron-donating ability, and thus decreased the π-based interactions between tetracycline and GO surface. Comparison of adsorption efficiency at different pH indicated that electrostatic interaction also played an important role in tetracycline-GO interactions. Site energy analysis confirmed a highly heterogeneous distribution of the binding sites and strong tetracycline binding affinity of GO surface. Copyright © 2017. Published by Elsevier B.V.

  19. Changes in weight and body fat after use of tetracycline and Lactobacillus gasseri in rats

    Directory of Open Access Journals (Sweden)

    Jorge José Marciano

    2017-04-01

    Full Text Available ABSTRACT Recent studies have shown a role of intestinal microbiota in obesity. The consumption of antibiotics in the last 70 years has led to changes in intestinal microbiota, which has led to weight gain and body fat accumulation. To evaluate the possibility of weight gain induced by antibiotics and the possible protective effect of probiotics, we divided 45 animals (Rattus norvegicus into groups and administered the following treatments over two weeks: tetracycline, tetracycline + Lactobacillus gasseri, and NaCl. The animals were weighed over the course of 8 weeks, and at the end of the treatment period, they were measured and subjected to bioelectrical impedance analysis. The results show that the group receiving tetracycline alone had a higher body mass index (p=0.030, a greater Lee index (p=0.008, and a lower body water percentage than the control group, indicating a greater accumulation of body fat. The group receiving the probiotics with tetracycline presented similar results to the control group, indicating a possible protective effect of body fat accumulation in the group receiving tetracycline alone. The results show that tetracycline increased the concentration of body fat, and the use of probiotics was associated with an ability to protect the animals from the pro-obesity effect.

  20. Rapid colorimetric sensing of tetracycline antibiotics with in situ growth of gold nanoparticles.

    Science.gov (United States)

    Shen, Li; Chen, Jing; Li, Na; He, Pingli; Li, Zhen

    2014-08-11

    A colorimetric assay utilizing the formation of gold nanoparticles was developed to detect tetracycline antibiotics in fluidic samples. Tetracycline antibiotics showed the capability of directly reducing aurate salts into atomic gold which form gold nanoparticles spontaneously under proper conditions. The resulted gold nanoparticles showed characteristic plasmon absorbance at 526 nm, which can be visualized by naked eyes or with a spectrophotometer. UV-vis absorbance of the resulted gold nanoparticles is correlated directly with the concentrations of tetracycline antibiotics in the solution, allowing for quantitative colorimetric detection of tetracycline antibiotics. Reaction conditions, such as pH, temperature, reaction time, and ionic strength were optimized. Sensitivity of the colorimetric assay can be enhanced by the addition of gold nanoparticle seeds, a LOD as low as 20 ng mL(-1) can be achieved with the help of seed particles. The colorimetric assay showed minimum interference from ethanol, methanol, urea, glucose, and other antibiotics such as sulfonamides, amino glycosides etc. Validity of the method was also evaluated on urine samples spiked with tetracycline antibiotics. The method provides a broad spectrum detection method for rapid and sensitive detection of reductive substances such as tetracycline antibiotics in liquid and biological samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Instability of chlorophyll in yellow lupin seedlings grown in soil contaminated with ciprofloxacin and tetracycline.

    Science.gov (United States)

    Rydzyński, Dariusz; Piotrowicz-Cieślak, Agnieszka I; Grajek, Hanna; Michalczyk, Dariusz J

    2017-10-01

    With increasing soil concentrations of ciprofloxacin and tetracycline a decrease of leaf chlorophyll content was observed. Tetracycline was more detrimental than ciprofloxacin. The chlorophyll content in plants growing for ten days on a tetracycline containing soil decreased by 68%. The decrease of chlorophyll concentration was even sharper in new leaves that formed after application of the antibiotic (up to 81% drop). The comparison of absorption spectra of commercial, reagent grade chlorophyll, alone and incubated with antibiotics, has shown that ciprofloxacin and tetracycline can react directly with chlorophyll and decrease its concentration by 47.7% and 48.5%, respectively. The changes in fluorescence spectra confirmed the formation of chlorophyll degradation product. The chlorophyll decay was a second order reaction and depended on antibiotic concentration and duration of exposure. Reaction rate constants differed with antibiotics and their soil concentrations. With increasing contents of antibiotics in soil the constant of chlorophyll degradation rate in lupin plants increased from k = 870 M -1 day -1 for 3 mg ciprofloxacin to k = 2490 M -1 day -1 for 90 mg ciprofloxacin, and in the case of tetracycline the reaction rate constant increased from k = 1330 M -1 day -1 to k = 2910 M -1 day -1 . The sensitivity of chlorophyll to ciprofloxacin and tetracycline was confirmed by determining EC and TU indices. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Tetracycline compounds with non-antimicrobial organ protective properties: possible mechanisms of action

    Science.gov (United States)

    Griffin, Michael O.; Ceballos, Guillermo; Villarreal, Francisco

    2010-01-01

    Tetracyclines were developed as a result of the screening of soil samples for antibiotics. The firstt of these compounds, chlortetracycline, was introduced in 1947. Tetracyclines were found to be highly effective against various pathogens including rickettsiae, as well as both gram-positive and gram-negative bacteria, thus becoming the first class of broad spectrum antibiotics. Many other interesting properties, unrelated to their antibiotic activity, have been identified for tetracyclines which have led to widely divergent experimental and clinical uses. For example, tetracyclines are also an effective anti-malarial drug. Minocycline, which can readily cross cell membranes, is known to be a potent anti-apoptotic agent. Another tetracycline, doxycycline is known to exert anti-protease activities. Doxycycline can inhibit matrix metalloproteinases which contribute to tissue destruction activities in diseases such as periodontitis. A large body of literature has provided additional evidence for the “beneficial” actions of tetracyclines, including their ability to act as reactive oxygen species scavengers and anti-inflammatory agents. This review provides a summary of tetracycline’s multiple mechanisms of action as a means to understand their beneficial effects. PMID:20951211

  3. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2013. Scientific Opinion on Carbapenem resistance in food animal ecosystems

    DEFF Research Database (Denmark)

    Hald, Tine; Baggesen, Dorte Lau

    -1-encoding genes were located on IncHI2 plasmids. A methodology including selective culture is proposed for the detection of CP strains of Enterobacteriaceae and Acinetobacter spp. The choice of selective media for the surveillance of carbapenem resistance for testing animal and food samples needs...... and effective option. As genes encoding carbapenemase production are mostly plasmid-mediated, and co-resistance may be an important issue in the spread of such resistance mechanisms, decreasing the frequency of use of antimicrobials in animal production in the EU in accordance with prudent use guidelines......Carbapenems are broad-spectrum β-lactam antimicrobials used for the treatment of serious infections in humans. To date only sporadic studies have reported the occurrence of carbapenemase-producing (CP) bacteria in food-producing animals and their environment. The bacteria and enzymes isolated...

  4. Sorptive removal of tetracycline from water by palygorskite

    International Nuclear Information System (INIS)

    Chang, Po-Hsiang; Li, Zhaohui; Yu, Tsai-Luen; Munkhbayer, Sandagdori; Kuo, Tzu-Hsing; Hung, Yu-Chiao; Jean, Jiin-Shuh; Lin, Kao-Hung

    2009-01-01

    Extensive use of pharmaceuticals and growth hormone in farm animal and live stocks has resulted in their frequent detection in soils, groundwater, and wastewater. The fate and transport of these compounds are strongly affected by their sorptive behavior to the soil minerals and humic materials. In this research, we conducted the sorption of tetracycline (TC), a common antibiotic, on palygorskite (PFL-1), a fibrous clay mineral of high surface area and high sorptivity towards organic compounds. The results showed that the sorption capacity of TC on PFL-1 was as high as 210 mmol/kg at pH 8.7. The sorption was relatively fast and reached equilibrium in 2 h. Solution pH and ionic strength had significant effects on TC sorption. The sorption of TC by palygorskite is endothermic and the free energy of sorption is in the range of -10 to -30 kJ/mol, suggesting a strong physical sorption. The X-ray diffraction patterns before and after TC sorption revealed no changes in d-spacing and intensity under different pH and initial TC concentrations, indicating that the sorbed TC molecules are on the external surface of the mineral in contrast to intercalation of TC into swelling clays, such as montmorillonite. The small positive value of entropy change suggested that TC molecules are in disordered arrangement on palygorskite surfaces. Surface sorption of TC on PFL-1 is further supported by the derivative of gravimetric analysis and by the calculation of the amount of TC sorption normalized to the surface area. The results suggest that palygorskite could be a good candidate to remove TC from wastewater containing higher amounts of TC.

  5. Interaction between tetracycline and smectite in aqueous solution.

    Science.gov (United States)

    Li, Zhaohui; Chang, Po-Hsiang; Jean, Jiin-Shuh; Jiang, Wei-Teh; Wang, Chih-Jen

    2010-01-15

    The fate and transport of commonly used antibiotics in soil and groundwater have attracted renewed studies due to increased sensitivities of analytical instruments and thus frequent detections of these compounds even in treated wastewater. Smectite, an important soil component, has large surface area and high cation exchange capacity, while tetracycline (TC) can exist in different forms and charges under different pH conditions. Thus, the interaction between smectite and TC in aqueous systems is of great importance. This research focused on elucidating the mechanisms of TC uptake by smectite, in terms of TC adsorption, cation desorption, and pH changes associated with TC adsorption by smectite and intercalation in smectite. TC adsorption onto smectite was a relatively fast process even though most of the adsorption sites were in the interlayer position involved in intercalation as confirmed by the expansion of d(001) spacing. The TC adsorption capacity was equivalent to 0.74-1.11 times the cation exchange capacity for three of the four smectite minerals studied. Accompanying TC adsorption was simultaneous adsorption of H(+), resulting in protonation of TC on the dimethylamine group. At higher TC input concentrations further adsorption of H(+) resulted in the ratio of H(+) adsorbed to TC adsorbed greater than one, suggesting that additionally adsorbed H(+) could serve as counterions to partially offset the negative charges on the tricarbonyl or phenolic diketone functional groups. The positive correlations between cations desorbed and TC adsorbed, as well as TC adsorbed and H(+) adsorbed, provided a first time evidence to confirm cation exchange as the main mechanism of TC uptake, even under neutral pH conditions.

  6. Content of biogenic amines in Lemna minor (common duckweed) growing in medium contaminated with tetracycline.

    Science.gov (United States)

    Baciak, Michał; Sikorski, Łukasz; Piotrowicz-Cieślak, Agnieszka I; Adomas, Barbara

    2016-11-01

    Aquatic plants are continuously exposed to a variety of stress factors. No data on the impact of antibiotics on the biogenic amines in duckweed (Lemna minor) have been available so far, and such data could be significant, considering the ecological role of this plant in animal food chains. In the tissues of control (non-stressed) nine-day-old duckweed, the following biogenic amines were identified: tyramine, putrescine, cadaverine, spermidine and spermine. Based on the tetracycline contents and the computed EC values, the predicted toxicity units have been calculated. The obtained results demonstrated phytoxicity caused by tetracycline in relation to duckweed growth rate, yield and the contents of chlorophylls a and b. The carotenoid content was not modified by tetracycline. It was found that tetracycline as a water pollutant was a stress factor triggering an increase in the synthesis of amines. Tetracycline at 19, 39 and 78μM concentrations increased biogenic amine synthesis by 3.5 times. Although the content of tyramine increased fourteen times with the highest concentration of the drug (and of spermidine - only three-fold) the increase of spermidine was numerically the highest. Among the biogenic amines the most responsive to tetracycline were spermine and tyramine, while the least affected were putrescine and spermidine. Despite putrescine and spermidine being the least sensitive, their sum of contents increased five-fold compared to the control. These studies suggest that tetracycline in water reservoirs is taken up by L. minor as the antibiotic clearly modifies the metabolism of this plant and it may likely pose a risk. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Tetracycline removal during wastewater treatment in high-rate algal ponds

    International Nuclear Information System (INIS)

    Godos, Ignacio de; Muñoz, Raúl; Guieysse, Benoit

    2012-01-01

    Highlights: ► Tetracycline removal was most likely caused by photodegradation and biosorption. ► Tetracycline presence was linked to biomass deflocculation and poor settleability. ► Deflocculation did not impact treatment efficiency. ► Deflocculation may hamper biomass recover during full-scale treatment. - Abstract: With the hypothesis that light supply can impact the removal of veterinary antibiotics during livestock wastewater treatment in high rate algal ponds (HRAPs), this study was undertaken to determine the mechanisms of tetracycline removal in these systems. For this purpose, two HRAPs were fed with synthetic wastewater for 46 days before tetracycline was added at 2 mg L −1 to the influent of one of the reactors (Te-HRAP). From day 62, dissolved tetracycline removal stabilized around 69 ± 1% in the Te-HRAP and evidence from batch assays suggests that this removal was mainly caused by photodegradation and biosorption. Tetracycline addition was followed by the deflocculation of the Te-HRAP biomass but had otherwise no apparent impact on the removal of the chemical oxygen demand (COD) and biomass productivity. The results from the batch assays also suggested that the light-shading and/or pollutant-sequestrating effects of the biomass limited tetracycline removal in the pond. For the first time, these results demonstrate that the shallow geometry of HRAPs is advantageous to support the photodegradation of antibiotics during wastewater biological treatment but that the presence of these pollutants could hamper biomass recovery. These findings have significant implications for algal-based environmental biotechnologies and must be confirmed under field conditions.

  8. Low rates of antimicrobial-resistant Enterobacteriaceae in wildlife in Taï National Park, Côte d'Ivoire, surrounded by villages with high prevalence of multiresistant ESBL-producing Escherichia coli in people and domestic animals.

    Science.gov (United States)

    Albrechtova, Katerina; Papousek, Ivo; De Nys, Helene; Pauly, Maude; Anoh, Etile; Mossoun, Arsene; Dolejska, Monika; Masarikova, Martina; Metzger, Sonya; Couacy-Hymann, Emmanuel; Akoua-Koffi, Chantal; Wittig, Roman M; Klimes, Jiri; Cizek, Alois; Leendertz, Fabian H; Literak, Ivan

    2014-01-01

    Antimicrobial resistance genes can be found in all ecosystems, including those where antibiotic selective pressure has never been exerted. We investigated resistance genes in a collection of faecal samples of wildlife (non-human primates, mice), people and domestic animals (dogs, cats) in Côte d'Ivoire; in the chimpanzee research area of Taï National Park (TNP) and adjacent villages. Single bacteria isolates were collected from antibiotic-containing agar plates and subjected to molecular analysis to detect Enterobacteriaceae isolates with plasmid-mediated genes of extended-spectrum beta-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR). While the prevalence of ESBL-producing E. coli in the villages was 27% in people (n = 77) and 32% in dogs (n = 38), no ESBL-producer was found in wildlife of TNP (n = 75). PMQR genes, mainly represented by qnrS1, were also present in human- and dog-originating isolates from the villages (36% and 42% in people and dogs, respectively), but no qnrS has been found in the park. In TNP, different variants of qnrB were detected in Citrobacter freundii isolates originating non-human primates and mice. In conclusion, ESBL and PMQR genes frequently found in humans and domestic animals in the villages were rather exceptional in wildlife living in the protected area. Although people enter the park, the strict biosecurity levels they are obliged to follow probably impede transmission of bacteria between them and wildlife.

  9. Antimicrobial resistance and resistance gene determinants in clinical Escherichia coli from different animal species in Switzerland.

    Science.gov (United States)

    Lanz, Roland; Kuhnert, Peter; Boerlin, Patrick

    2003-01-02

    Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.

  10. Biosynthesis of Oxytetracycline by Streptomyces rimosus: Past, Present and Future Directions in the Development of Tetracycline Antibiotics

    Directory of Open Access Journals (Sweden)

    Hrvoje Petković

    2017-01-01

    Full Text Available Natural tetracycline (TC antibiotics were the first major class of therapeutics to earn the distinction of ‘broad-spectrum antibiotics’ and they have been used since the 1940s against a wide range of both Gram-positive and Gram-negative pathogens, mycoplasmas, intracellular chlamydiae, rickett siae and protozoan parasites. The second generation of semisynthetic tetracyclines, such as minocycline and doxycycline, with improved antimicrobial potency, were introduced during the 1960s. Despite emerging resistance to TCs erupting during the 1980s, it was not until 2006, more than four decades later, that a third-generation TC, named tigecycline, was launched. In addition, two TC analogues, omadacycline and eravacycline, developed via (semisynthetic and fully synthetic routes, respectively, are at present under clinical evaluation. Interestingly, despite very productive early work on the isolation of a Streptomyces aureofaciens mutant strain that produced 6-demethyl-7-chlortetracycline, the key intermediate in the production of second- and third-generation TCs, biosynthetic approaches in TC development have not been productive for more than 50 years. Relatively slow and tedious molecular biology approaches for the genetic manipulation of TC-producing actinobacteria, as well as an insufficient understanding of the enzymatic mechanisms involved in TC biosynthesis have significantly contributed to the low success of such biosynthetic engineering efforts. However, new opportunities in TC drug development have arisen thanks to a signifi cant progress in the development of affordable and versatile biosynthetic engineering and synthetic biology approaches, and, importantly, to a much deeper understanding of TC biosynthesis, mostly gained over the last two decades.

  11. Development and validation of an HPLC method for tetracycline-related USP monographs.

    Science.gov (United States)

    Hussien, Emad M

    2014-09-01

    A novel reversed-phase HPLC method was developed and validated for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline hydrochloride impurity in tetracycline hydrochloride commercial bulk and pharmaceutical products. The method employed L1 (3 µm, 150 × 4.6 mm) columns, a mobile phase of 0.1% phosphoric acid and acetonitrile at a flow rate of 1.0 mL/min, and detection at 280 nm. The separation was performed in HPLC gradient mode. Forced degradation studies showed that tetracycline eluted as a spectrally pure peak and was well resolved from its degradation products. The fast degradation of tetracycline hydrochloride and 4-epianhydrotetracycline hydrochloride in solution was retarded by controlling the autosampler temperature at 4 °C and using 0.1% H3 PO4 as diluent. The robustness of the method was tested starting with the maximum variations allowed in the US Pharmacopeia (USP) general chapter Chromatography . The method was linear over the range 80-120% of the assay concentration (0.1 mg/mL) for tetracycline hydrochloride and 50-150% of the acceptance criteria specified in the individual USP monographs for 4-epianhydrotetracycline hydrochloride. The limit of quantification for 4-epianhydrotetracycline hydrochloride was 0.1 µg/mL, 20 times lower than the acceptance criteria. The method was specific, precise, accurate and robust. Copyright © 2014 John Wiley & Sons, Ltd.

  12. In vitro susceptibility pattern of extended spectrum ?-lactamase producing gram negative bacilli against tetracyclines

    International Nuclear Information System (INIS)

    Gill, M.M.

    2015-01-01

    Extended Spectrum beta-lactamases (ESBLs) are emerging as common nosocomial pathogens and important cause of mortality and morbidity, if not treated properly. The need of the hour is to find effective treatment options for dealing with ESBL producing organisms. This study was aimed to evaluate in vitro susceptibility pattern of extended spectrum beta-lactamase producers against tetracyclines. Methods: This descriptive cross-sectional study was carried out in the department of Microbiology, Army Medical College, Rawalpindi, National University of Sciences and Technology over a period of 6 months. Seventy eight non-duplicate isolates were included in the study. ESBL detection was done using Jarlier et al method. In vitro susceptibility of tetracyclines like tetracycline, doxycycline, minocycline and tigecycline was then tested using Modified Kirby Bauer disc diffusion method. The zones of inhibition were measured after completion of incubation period and interpreted as per CLSI and FDA guidelines. Results: Approximately 56.4% of the isolates were Escherichia coli, 28.2% were Klebsiella pneumoniae, 10.26% were Enterobacter species, and 2.6% were each Klebsiella oxytoca and Acinetobacter species. ESBLs were found to be most sensitive to tigecycline, intermediate in susceptibility to minocycline while least sensitive to doxycycline and tetracycline. Conclusion: Among tetracyclines, tigecycline has best in vitro susceptibility against ESBL producing Gram negative rods. (author)

  13. BIOCHEMICAL AND HISTOLOGICAL EFFECTS OF TETRACYCLINES ON SPONTANEOUS OSTEOARTHRITIS IN GUINEA PIGS

    Directory of Open Access Journals (Sweden)

    Edin De Bri

    2011-05-01

    Full Text Available Matrix metalloproteinases (MMPs are mediators in connective tissue destruction in a variety of pathologic processes. Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of MMP mediated connective tissue degradation in both rheumatoid arthritis (RA and osteoarthritis (OA. The Hartley guinea pig model has been described with a high incidence of spontaneous OA-like changes in the knee joint. Therefore we have studied the effect of two tetracyclines, doxycycline (Dox and chemically modified tetracycline-7 (CMT-7 which have both previously been shown as potent MMP inhibitors. We found that prophylactic orally given CMT-7 decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. OA changes were most severe in the central compartment of the medial condyle in the control group. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation were all less in the CMT-7 treated group compared with controls. Collagen, hyaluronan and proteoglycan content in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. These results show that tetracyclines, but not all tetracyclines, can reduce the severity of OA in the guinea pig model of spontaneous OA.

  14. Gel entrapment culture of rat hepatocytes for investigation of tetracycline-induced toxicity

    International Nuclear Information System (INIS)

    Shen Chong; Meng Qin; Schmelzer, Eva; Bader, Augustinus

    2009-01-01

    This paper aimed to explore three-dimensionally cultured hepatocytes for testing drug-induced nonalcoholic steatohepatitis. Gel entrapped rat hepatocytes were applied for investigation of the tetracycline-induced steatohepatitis, while hepatocyte monolayer was set as a control. The toxic responses of hepatocytes were systematically evaluated by measuring cell viability, liver-specific function, lipid accumulation, oxidative stress, adenosine triphosphate content and mitochondrial membrane potential. The results suggested that gel entrapped hepatocytes showed cell death after 96 h of tetracycline treatment at 25 μM which is equivalent to toxic serum concentration in rats, while hepatocyte monolayer showed cell death at a high dose of 200 μM. The concentration-dependent accumulation of lipid as well as mitochondrial damage were regarded as two early events for tetracycline hepatotoxicity in gel entrapment culture due to their detectability ahead of subsequent increase of oxidative stress and a final cell death. Furthermore, the potent protection of fenofibrate and fructose-1,6-diphosphate were evidenced in only gel entrapment culture with higher expressions on the genes related to β-oxidation than hepatocyte monolayer, suggesting the mediation of lipid metabolism and mitochondrial damage in tetracycline toxicity. Overall, gel entrapped hepatocytes in three-dimension reflected more of the tetracycline toxicity in vivo than hepatocyte monolayer and thus was suggested as a more relevant system for evaluating steatogenic drugs.

  15. 蛋白涂层支架携带一氧化氮合酶基因转染%The Feasibility of Local Plasmid-Mediated Human Inducible Nitri c Oxide Synthase Gene Transfer to Coronary Artery with Protein-Coated Metallic Stents in Mini-Swine Model

    Institute of Scientific and Technical Information of China (English)

    戴军; 高润霖; 汤健; 宋来凤; 魏英杰; 宋莉; 李永利; 唐承君; 史瑞文

    2001-01-01

    Objective:To assess the feasibility of plasmid-medicated local transfer of inducible nitric oxide synthase (iNOS) gene to coronary artery using protein-co ated metallic stents in mini-swine medel.   Methods:The metallic stent was coated by cross-linked gelatin and mounted o n 3.0 mm Percutaneous transluminal coronary angioplasty (PTCA) balloon,then End otoxin-free ultrapure Endotoxin-free ultrapure Plasmid pcDNA3hepiNOS under the control of the comegalovirus (CMV) promoter/enhancer was absorbed on the stent. Protein-coated stainless steel stents were used as controls.All stents were imp lanted into the middle segment of left anterior descending artery through 7F lar ge luman gui ding catheter.(The ratio of balloon to vessel diameter was 1.1-1.3∶1).Total RNA of stented segment of coronary artery was extracted,its reverse transeriptio n polymerase chain reaction (RT-PCR) and immunohistochemical staining were perf ormed through routine methods.   Results:At the 7th day after stenting,RT-PCR and immunohistochemical staining confirmed the expression of plasmid pcDNA3hepiNOS mRNA and presence of its protein at gene transered vessels (n=2) but there was no expression in remote organs.Endothelialization of the vessel was observed in all animals throu gh scanning electromicroscopy.   Conclusions:Local plasmid-mediated human inducible nitric oxide synthase ge ne transfer to coronary artery with protein-coated metallic stents is feasible in mini-swine model.%目的:探索蛋白涂层支架携带质粒介导人肝脏诱导型一氧化氮合酶(iNOS)基因转染小型猪冠状动脉可行性。 方法:使用蛋白支架吸附去内毒素纯化质粒,以常规支架置入技术置入小型猪冠状动脉前降支中段。置入后第7天取出前降支置入段,分别提取总核糖核酸(RAN)并进行逆向多聚酶链反应(RT-PCR),免疫组化染色检测导入人肝脏iNOS蛋白的表达。 结果:小型猪前降支置入支架处显示人iNOS基

  16. How Fitness Reduced, Antimicrobial Resistant Bacteria Survive and Spread

    DEFF Research Database (Denmark)

    Græsbøll, Kaare; Nielsen, Søren Saxmose; Toft, Nils

    2014-01-01

    More than 30% of E. coli strains sampled from pig farms in Denmark over the last five years were resistant to the commonly used antimicrobial tetracycline. This raises a number of questions: How is this high level sustained if resistant bacteria have reduced growth rates? Given that there are mul...

  17. Mechanism of quinolone action and resistance.

    Science.gov (United States)

    Aldred, Katie J; Kerns, Robert J; Osheroff, Neil

    2014-03-18

    Quinolones are one of the most commonly prescribed classes of antibacterials in the world and are used to treat a variety of bacterial infections in humans. Because of the wide use (and overuse) of these drugs, the number of quinolone-resistant bacterial strains has been growing steadily since the 1990s. As is the case with other antibacterial agents, the rise in quinolone resistance threatens the clinical utility of this important drug class. Quinolones act by converting their targets, gyrase and topoisomerase IV, into toxic enzymes that fragment the bacterial chromosome. This review describes the development of the quinolones as antibacterials, the structure and function of gyrase and topoisomerase IV, and the mechanistic basis for quinolone action against their enzyme targets. It will then discuss the following three mechanisms that decrease the sensitivity of bacterial cells to quinolones. Target-mediated resistance is the most common and clinically significant form of resistance. It is caused by specific mutations in gyrase and topoisomerase IV that weaken interactions between quinolones and these enzymes. Plasmid-mediated resistance results from extrachromosomal elements that encode proteins that disrupt quinolone-enzyme interactions, alter drug metabolism, or increase quinolone efflux. Chromosome-mediated resistance results from the underexpression of porins or the overexpression of cellular efflux pumps, both of which decrease cellular concentrations of quinolones. Finally, this review will discuss recent advancements in our understanding of how quinolones interact with gyrase and topoisomerase IV and how mutations in these enzymes cause resistance. These last findings suggest approaches to designing new drugs that display improved activity against resistant strains.

  18. Prevalence of quinolone resistance mechanisms in Enterobacteriaceae producing acquired AmpC β-lactamases and/or carbapenemases in Spain.

    Science.gov (United States)

    Machuca, Jesús; Agüero, Jesús; Miró, Elisenda; Conejo, María Del Carmen; Oteo, Jesús; Bou, Germán; González-López, Juan José; Oliver, Antonio; Navarro, Ferran; Pascual, Álvaro; Martínez-Martínez, Luis

    2017-10-01

    Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates. The presence of chromosomal- and plasmid-mediated quinolone resistance mechanisms [mutations in the quinolone resistance determining region (QRDR) of gyrA and parC and qnr, aac(6')-Ib-cr and qepA genes] was evaluated in 289 isolates of acquired AmpC β-lactamase- and/or carbapenemase-producing Enterobacteriaceae collected between February and July 2009 in 35 Spanish hospitals. Plasmid mediated quinolone resistance (PMQR) genes were detected in 92 isolates (31.8%), qnr genes were detected in 83 isolates (28.7%), and the aac(6')-Ib-cr gene was detected in 20 isolates (7%). qnrB4 gene was the most prevalent qnr gene detected (20%), associated, in most cases, with DHA-1. Only 14.6% of isolates showed no mutations in gyrA or parC with a ciprofloxacin MIC of 0.5mg/L or higher, whereas PMQR genes were detected in 90% of such isolates. qnrB4 gene was the most prevalent PMQR gene detected, and was significantly associated with acquired AmpC β-lactamase DHA-1. PMQR determinants in association with other chromosomal-mediated quinolone resistance mechanisms, different to mutations in gyrA and parC (increased energy-dependent efflux, altered lipopolysaccharide or porin loss), could lead to ciprofloxacin MIC values that exceed breakpoints established by the main international committees to define clinical antimicrobial susceptibility breakpoints. Copyright © 2016 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  19. Fate of antibiotic resistant bacteria and genes during wastewater chlorination: implication for antibiotic resistance control.

    Directory of Open Access Journals (Sweden)

    Qing-Bin Yuan

    Full Text Available This study investigated fates of nine antibiotic-resistant bacteria as well as two series of antibiotic resistance genes in wastewater treated by various doses of chlorine (0, 15, 30, 60, 150 and 300 mg Cl2 min/L. The results indicated that chlorination was effective in inactivating antibiotic-resistant bacteria. Most bacteria were inactivated completely at the lowest dose (15 mg Cl2 min/L. By comparison, sulfadiazine- and erythromycin-resistant bacteria exhibited tolerance to low chlorine dose (up to 60 mg Cl2 min/L. However, quantitative real-time PCRs revealed that chlorination decreased limited erythromycin or tetracycline resistance genes, with the removal levels of overall erythromycin and tetracycline resistance genes at 0.42 ± 0.12 log and 0.10 ± 0.02 log, respectively. About 40% of erythromycin-resistance genes and 80% of tetracycline resistance genes could not be removed by chlorination. Chlorination was considered not effective in controlling antimicrobial resistance. More concern needs to be paid to the potential risk of antibiotic resistance genes in the wastewater after chlorination.

  20. Antibiotic-resistant genes and antibiotic-resistant bacteria in the effluent of urban residential areas, hospitals, and a municipal wastewater treatment plant system.

    Science.gov (United States)

    Li, Jianan; Cheng, Weixiao; Xu, Like; Strong, P J; Chen, Hong

    2015-03-01

    In this study, we determined the abundance of 8 antibiotics (3 tetracyclines, 4 sulfonamides, and 1 trimethoprim), 12 antibiotic-resistant genes (10 tet, 2 sul), 4 antibiotic-resistant bacteria (tetracycline, sulfamethoxazole, and combined resistance), and class 1 integron integrase gene (intI1) in the effluent of residential areas, hospitals, and municipal wastewater treatment plant (WWTP) systems. The concentrations of total/individual targets (antibiotics, genes, and bacteria) varied remarkably among different samples, but the hospital samples generally had a lower abundance than the residential area samples. The WWTP demonstrated removal efficiencies of 50.8% tetracyclines, 66.8% sulfonamides, 0.5 logs to 2.5 logs tet genes, and less than 1 log of sul and intI1 genes, as well as 0.5 log to 1 log removal for target bacteria. Except for the total tetracycline concentration and the proportion of tetracycline-resistant bacteria (R (2) = 0.330, P antibiotics and the corresponding resistant bacteria (P > 0.05). In contrast, various relationships were identified between antibiotics and antibiotic resistance genes (P antibiotic-resistant bacteria (P < 0.01).

  1. Occurrence and Distribution of Antibiotic-resistant Bacteria and Transfer of Resistance Genes in Lake Taihu

    OpenAIRE

    Yin, Qian; Yue, Dongmei; Peng, Yuke; Liu, Ying; Xiao, Lin

    2013-01-01

    The overuse of antibiotics has accelerated antibiotic resistance in the natural environment, especially fresh water, generating a potential risk for public health around the world. In this study, antibiotic resistance in Lake Taihu was investigated and this was the first thorough data obtained through culture-dependent methods. High percentages of resistance to streptomycin and ampicillin among bacterial isolates were detected, followed by tetracycline and chloramphenicol. Especially high lev...

  2. Tetracycline residues in porcine stomach after administration via drinking water on a swine farm.

    Science.gov (United States)

    Lindquist, Danielle; Wu, Huali; Mason, Sharon; Yeatts, Jim; Brooks, Jim; Barlow, Beth; Schill, Kaitlyn; Baynes, Ronald

    2014-01-01

    Tetracycline is a broad-spectrum antibiotic used to treat infections in swine. The maximum residue levels of tetracycline in pork stomach tissue in Russia, Europe, and the United States are 10, 200, and 2,000 ppb, respectively. This difference in accepted safety levels may be the reason why stomach tissues that the United States exports continue to be residue violators in overseas markets. In this study, 30 pigs at two different stages of production (weanling and finisher) were treated with tetracycline at 22 mg/kg of body weight per day for a total of 5 days via a water medicator. Blood samples were collected at 0, 72, 78, 96, and 102 h after the start of medication. The medication was stopped at 120 h, and blood samples were again collected at 126, 144, 168, 192, and 216 h after exposure. Five animals were slaughtered for stomach tissue 0, 24, 48, 96, and 192 h after the drug was flushed from the water line. All blood and tissue samples were analyzed by high-performance liquid chromatography-UV methods. The tetracycline levels in plasma were below the level of detection after the U.S.-labeled withdrawal time of 4 days. The stomach tissue residues averaged 671.72, 330.31, 297.77, 136.36, and 268.08 ppb on withdrawal days 0, 1, 2, 4, and 8, respectively. Using the U.S. Food and Drug Administration tolerance limit method and a population-based pharmacokinetic model with Monte Carlo simulation, a withdrawal interval was estimated. This study demonstrated that tetracycline residues are still detectable in the stomach tissues after the established United States withdrawal time of 4 days. These residue levels may explain why stomach tissues tested in Russia and Europe show positive residues for tetracycline, even though the meat may pass inspection here in the United States prior to export.

  3. Study of the behaviour of tetracycline as fission products extracting agent

    International Nuclear Information System (INIS)

    Cunha, I.I.L.

    1983-01-01

    Both spectrophotometric and potentiometric titration techniques were used to show the formation of complexes between tetracycline and the elements: zirconium, uranium, molybdenum, strontium, barium and ruthenium. It has been verified that tetracycline does not form complexes with cesium, tellurium and iodine. Those techniques have also been used to determine the sites on the tetracycline molecule at which ions may be bound. The behaviour of tetracycline as an extracting agent for those elements, as well as for niobium and technetium has been studied and the influence of the acidity of the aqueous phase upon extraction of the elements mentioned has been considered. Extraction experiments were carried out in the presence of chloride, perchlorate, nitrate and sulfate ions. Studies have been made to determine whether or not the complex extracted into organic phase is really the complex formed between tetracycline and the elements considered as well as to determine the time of shaking necessary so that the equilibrium between the phases is attained. Based on all information obtained from extraction experiments made for uranium and the fission products Zr-95, Nb-95, Ce-141, La-140, Ru-103, Ba-140 and Cs-137, the possibility of using tetracycline for separating those fission products from each other and from uranium has been studies and a scheme for simultaneous separation of those elements has been proposed. The same study has been made for I-131, Tc-99m, Mo-99, Te-132, Np-239 and uranium. The method described is applicable to the separation of some fission products existing in solutions at tracer levels, and not to be used in nuclear fuel reprocessing or any other industrial application. (Author) [pt

  4. On the organ distribution of a selection of 99mTc-tagged tetracyclines

    International Nuclear Information System (INIS)

    Weinhold, S.E.M.

    1983-01-01

    During this study the time course of organ concentrations of 99mTc-tagged tetracycline and of 99mTc-rolitetracycline that had been labeled according to two different methods was investigated with reference to that of two standard preparations, 99mTcO 4 and 3 H-labeled tetracycline, which differ from the test substances in their chemical structures (lipohilia - hydrophilia). As the substances to be investigated here are chemically related, they showed mostly consistent organ concentrations and great vivo stability. The concentrations measured in the organs examined (particularly the lungs) followed the same pattern as the concentrations in the blood and were thus regarded as being primarily the result of convection processes, whereas the concentrations seen in some other organs (especially the kidneys and, to a lesser extent, the liver) rather appeared to be determined by invasion and evasion processes; this held true for 99mTc-labeled tetracyclines as well as for pertechnetate. None of the five substances tested during this study appeared to be able to pass the blood-brain barrier. As regards solubility in water, the 99mTc-labeled tetracyclines occupy an intermediate position between pertechnetate (extremely water-soluble) and 3 H-labeled tetracyclines (extremely lipophil), which can be seen from the moderately high blood concentrations of these preparations. In view of the high organ concentrations that are observed particularly in the kidneys following administration of 99mTc-labeled tetracycline and rolitetracycline, the use of these substances for renal scintiscanning appears worth considering, as only approx. one tenth of the dose of pertechnetate would be required for this purpose. (TRV) [de

  5. Effects of ultraviolet light on lecithin monolayers in the presence of fluorescein dyes and tetracycline drugs

    International Nuclear Information System (INIS)

    Riaz, M.; Pilpel, N.

    1983-01-01

    A Langmuir trough was employed to measure the effects of u.v. irradiation on the force area characteristics of monolayer films of lecithin spread on aqueous solutions of some dyes and tetracycline drugs both in the absence and presence of Cu 2 + and Ni 2 + . Irradiation caused photochemical reactions which resulted in the expansion of the films and the extent of reaction was measured by the Photosensitive Indices. The reaction with tetracyclines was inhibited by adding Cu 2 + or Ni 2 + to the substrate. The kinetic orders of the reactions are given. (author)

  6. Rejection of Tetracycline and Oxytetracycline in Water by a Nanofiltration Membrane

    Science.gov (United States)

    Li, Weiying; Sun, Xiuli; Wang, Qing; Xu, Jingjing; Lu, Junyu

    2010-11-01

    The removal of tetracycline (TC) and oxytetracycline (OTC) by a nanofiltration (NF) membrane was studied using synthetic solutions. The effects of operation parameters (recovery and flux), feed concentration and salinity on the rejection of tetracyclines and their adsorption on membranes were investigated. TC was observed to show a high adsorptive affinity for the membrane. Almost 80% of TC and 70% of OTC were adsorbed on the membrane surface after stirring for 2000 min and over 50% of them had been adsorbed just 120 min after stir. High removal efficiencies (>90%) were observed for TC and OTC with NF membrane. Rejection ratio of OTC by NF was slightly higher than that of TC.

  7. Effects of ultraviolet light on lecithin monolayers in the presence of fluorescein dyes and tetracycline drugs

    Energy Technology Data Exchange (ETDEWEB)

    Riaz, M; Pilpel, N [Chelsea Coll. of Science and Technology, London (UK)

    1983-04-01

    A Langmuir trough was employed to measure the effects of u.v. irradiation on the force area characteristics of monolayer films of lecithin spread on aqueous solutions of some dyes and tetracycline drugs both in the absence and presence of Cu/sup 2 +/ and Ni/sup 2 +/. Irradiation caused photochemical reactions which resulted in the expansion of the films and the extent of reaction was measured by the Photosensitive Indices. The reaction with tetracyclines was inhibited by adding Cu/sup 2 +/ or Ni/sup 2 +/ to the substrate. The kinetic orders of the reactions are given.

  8. Salmon Aquaculture and Antimicrobial Resistance in the Marine Environment

    Science.gov (United States)

    Buschmann, Alejandro H.; Tomova, Alexandra; López, Alejandra; Maldonado, Miguel A.; Henríquez, Luis A.; Ivanova, Larisa; Moy, Fred; Godfrey, Henry P.; Cabello, Felipe C.

    2012-01-01

    Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol) were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments. PMID:22905164

  9. Salmon aquaculture and antimicrobial resistance in the marine environment.

    Directory of Open Access Journals (Sweden)

    Alejandro H Buschmann

    Full Text Available Antimicrobials used in salmon aquaculture pass into the marine environment. This could have negative impacts on marine environmental biodiversity, and on terrestrial animal and human health as a result of selection for bacteria containing antimicrobial resistance genes. We therefore measured the numbers of culturable bacteria and antimicrobial-resistant bacteria in marine sediments in the Calbuco Archipelago, Chile, over 12-month period at a salmon aquaculture site approximately 20 m from a salmon farm and at a control site 8 km distant without observable aquaculture activities. Three antimicrobials extensively used in Chilean salmon aquaculture (oxytetracycline, oxolinic acid, and florfenicol were studied. Although none of these antimicrobials was detected in sediments from either site, traces of flumequine, a fluoroquinolone antimicrobial also widely used in Chile, were present in sediments from both sites during this period. There were significant increases in bacterial numbers and antimicrobial-resistant fractions to oxytetracycline, oxolinic acid, and florfenicol in sediments from the aquaculture site compared to those from the control site. Interestingly, there were similar numbers of presumably plasmid-mediated resistance genes for oxytetracycline, oxolinic acid and florfenicol in unselected marine bacteria isolated from both aquaculture and control sites. These preliminary findings in one location may suggest that the current use of large amounts of antimicrobials in Chilean aquaculture has the potential to select for antimicrobial-resistant bacteria in marine sediments.

  10. Bismuth-Based Quadruple Therapy with Bismuth Subcitrate, Metronidazole, Tetracycline and Omeprazole in the Eradication of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Raymond Lahaie

    2001-01-01

    Full Text Available BACKGROUND: A previous study showed that 14 days of qid bismuth-based triple therapy with tetracycline 500 mg, metronidazole 250 mg and colloidal bismuth subcitrate 120 mg resulted in excellent Helicobacter pylori eradication rates (89.5%. The present study looked at a shorter treatment period by adding omeprazole and by reducing the dose of tetracycline.

  11. Study of the effect of gamma radiation on the molecule of tetracycline concerning its behavior as complexing and extracting agent

    International Nuclear Information System (INIS)

    Andrade e Silva, Leonardo Gondim de

    1982-01-01

    Both solvent extraction and spectrophotometric techniques were used to show the alterations that gamma radiation causes in the behavior of tetracycline molecule as far as its extracting and complexing power are concerned. The effect of gamma radiation on the solid tetracycline molecule, benzyl alcohol and on the solution of both was examined in solvent extraction systems whose aqueous phases were made up by 152 Eu- 154 Eu radioactive tracer solutions and whose organic phases were constituted by tetracycline-benzyl alcohol solutions. Experiments were performed in order to determine whether or not the water used for the pre-saturation of benzyl alcohol would influence the radiolysis of tetracycline. Solvent extraction and spectrophotometry were the techniques used to obtain the necessary data. Absorption spectra of irradiated tetracycline benzyl alcohol solutions submitted to several gamma radiation doses were examined and the alterations shown by these spectra were examined. The effect of gamma radiation on the tetracycline molecule was also studied when tetracycline-benzyl alcohol solutions were irradiated under several gaseous atmospheres, namely: O 2 , N 2 , SF 6 and N 2 O. The variation on the concentration of the tetracycline-benzyl alcohol solution caused by several doses of gamma radiation was determined by using the spectrophotometric technique. (author)

  12. Rapid Increase in Prevalence of Carbapenem-Resistant Enterobacteriaceae (CRE) and Emergence of Colistin Resistance Gene mcr-1 in CRE in a Hospital in Henan, China.

    Science.gov (United States)

    Li, Yi; Sun, Qiao-Ling; Shen, Yingbo; Zhang, Yangjunna; Yang, Jun-Wen; Shu, Ling-Bin; Zhou, Hong-Wei; Wang, Yang; Wang, Bing; Zhang, Rong; Wang, Shaolin; Shen, Zhangqi

    2018-04-01

    The global spread of carbapenem-resistant Enterobacteriaceae (CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance gene mcr-1 among CRE strains greatly compromises the use of colistin as a last resort for the treatment of infections caused by CRE. This study aimed to understand the current epidemiological trends and characteristics of CRE from a large hospital in Henan, the most populous province in China. From 2014 to 2016, a total of 7,249 Enterobacteriaceae isolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistant Klebsiella pneumoniae and carbapenem-resistant Escherichia coli were the two most common CRE species, with Klebsiella pneumoniae carbapenemases (KPC) and New Delhi metallo-β-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% ( n = 589) of the K. pneumoniae isolates from the intensive care unit were carbapenem resistant. Furthermore, bla NDM-5 and mcr-1 were found to coexist in one E. coli isolate, which exhibited resistance to almost all tested antibiotics. Overall, we observed a significant increase in the prevalence of CRE isolates during the study period and suggest that carbapenems may no longer be considered to be an effective treatment for infections caused by K. pneumoniae in the studied hospital. Copyright © 2018 American Society for Microbiology.

  13. Resistance to nitrofurantoin and UV-irradiation in recA; uvrA; and uvrA, lexA, Escherichia coli mutants conferred by an R-plasmid from an Escherichia coli clinical isolate

    Energy Technology Data Exchange (ETDEWEB)

    Obaseiki-Ebor, E.E. (Univ. of Benin, Benin City (Nigeria). Faculty of Pharmacy, Dept. of Pharmaceutical Microbiology)

    1984-01-01

    There have been some reports of R-plasmids conferring nitrofuran resistance by decreasing the reduction of nitrofurantoin. The mechanism by which these R-plasmids mediate nitrofurantoin resistance is still not properly understood. Since DNA repair mutants are very sensitive to nitrofurantoin, it was therefore of interest to see whether R-plasmids conferring nitrofurantoin resistance affected the nitrofurantoin sensitivity of recA; uvrA and uvrA, lexA strains of E. coli K-12. Protection against UV-irradiation was also estimated. The experiments showed that the nitrofurantoin resistance conferred by R-plasmid pBN105 was not due to defective nitrofurantoin reduction or altered permeability of the cell. Because it is known that repair-deficient bacteria have increased susceptibility to nitrofurantoin, it may be suggested that the mechanisms of UV and nitrofurantoin protection conferred by pBN105 to the DNA repair mutant strains are related.

  14. Resistance to nitrofurantoin and UV-irradiation in recA; uvrA; and uvrA, lexA, Escherichia coli mutants conferred by an R-plasmid from an Escherichia coli clinical isolate

    International Nuclear Information System (INIS)

    Obaseiki-Ebor, E.E.

    1984-01-01

    There have been some reports of R-plasmids conferring nitrofuran resistance by decreasing the reduction of nitrofurantoin. The mechanism by which these R-plasmids mediate nitrofurantoin resistance is still not properly understood. Since DNA repair mutants are very sensitive to nitrofurantoin, it was therefore of interest to see whether R-plasmids conferring nitrofurantoin resistance affected the nitrofurantoin sensitivity of recA; uvrA and uvrA, lexA strains of E. coli K-12. Protection against UV-irradiation was also estimated. The experiments showed that the nitrofurantoin resistance conferred by R-plasmid pBN105 was not due to defective nitrofurantoin reduction or altered permeability of the cell. Because it is known that repair-deficient bacteria have increased susceptibility to nitrofurantoin, it may be suggested that the mechanisms of UV and nitrofurantoin protection conferred by pBN105 to the DNA repair mutant strains are related. (Auth.)

  15. The effectiveness of 0.5–0.7% tetracycline gel to reduced subgingival plaque bacteria

    Directory of Open Access Journals (Sweden)

    Ernie Maduratna Setiawati

    2008-09-01

    Full Text Available Background: The tetracycline was an antimicrobial agent, that a broad spectrum. In addition to the antimicrobial effects, their efficacy was also anticollagenase and removal of the smear layer on the root surface. Purpose: The aim of the study was to evaluate effectiveness tetracycline gel 0.5–0.7% to reduction subgingival plaque bacteria. Method: A laboratory experimental study was conducted to investigate the effectiveness tetracycline gel 0.5–0.7%. Samples were divided into 5 groups with different concentration. The antimicrobial effect was performed using spectrophotometer. The statistical test was used One-Way ANOVA with significant difference 5% and subsequently Tukey-HSD test. Result: The study showed that tetracycline gel 0.5% has the highest antimicrobial has the highest antimicrobial effect. Conclusion: Tetracycline gel with 0.5% concentration is effective in inhibiting the growth of subgingival plaque bacteria.

  16. Chemically modified tetracyclines stimulate matrix metalloproteinase-s production by periodontal ligament cells

    NARCIS (Netherlands)

    Bildt, M.M.; Snoek-van Beurden, A.M.P.; Groot, J. de; El, B. van; Kuijpers-Jagtman, A.M.; Hoff, J.W. van den

    2006-01-01

    Background and Objective: The purpose of this study was to investigate the effects of chemically modified tetracyclines (CMTs) on the production of gelatinases [matrix metalloproteinase (MMP)-2 and -9] by human periodontal ligament (PDL) cells, and on the activity of recombinant gelatinases.

  17. Mid-infrared spectroscopy and multivariate analysis for determination of tetracycline residues in cow's milk

    Directory of Open Access Journals (Sweden)

    Lizeth Mariel Casarrubias-Torres

    2018-01-01

    Full Text Available Mid-infrared spectroscopy and chemometric analysis were tested to determine tetracycline's residues in cow's milk. Cow's milk samples (n = 30 were spiked with tetracycline, chlortetracycline, and oxytetracycline in the range of 10-400 µg/l. Chemometric models to quantify each of the tetracycline's residues were developed by applying Partial Components Regression and Partial Least Squares algorithms. The Soft Independent Modeling of Class Analogy model was used to differentiate between pure milk and milk sample with tetracycline residues. The best models for predicting the levels of these antibiotics were obtained using Partial Least Square 1 algorithm (coefficient of determination between 0.997-0.999 and the standard error of calibration from 1.81 to 2.95. The Soft Independent Modeling of Class Analogy model showed well-separated groups allowing classification of milk samples and milk sample with antibiotics. The obtained results demonstrate the great analytical potential of chemometrics coupled with mid-infrared spectroscopy for the prediction of antibiotic in cow's milk at a concentration of microgram per litre (µg/l. This technique can be used to verify the safety of the milk rapidly and reliably.

  18. Determination of the stability constants for the complexes of rare-earth elements and tetracycline

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W.

    1977-01-01

    Stability constants for the lanthanide elements complexes with tetracycline were determined by the methods of average number of ligands, the two parameters and by weighted least squares. The technique of solvent extraction was applied to obtain the values of the parameters required for the determination of the constants [pt

  19. On the organ distribution of several 99mTc-labelled tetracyclines

    International Nuclear Information System (INIS)

    Weinhold, S.E.M.

    1983-01-01

    Experiments in rats have pointed to a high stability of 99m Tc-labelled tetracyclines, which are found in vivo in the form of chemically stable chelate complexes. Their biokinetic behaviour in most organs (the lungs) and the blood is predominantly determined by convection processes. In other organs (notably the kidneys and, to a lesser extent, the liver and spleen) their passage can be described in terms of influx and efflux, with accumulation, metabolisation and excretion of the drug administered being the main steps involved. 3 H-Labelled tetracyclines are chemically unchanged tetracyclines showing pronounced lipophilia that tend to be taken up and eliminated via influx and efflux processes in the large majority of organs. The highest blood levels were measured for 99m TcO 4 , which is a hydrophilic substance. None of the substances tested appeared to be able to cross the blood-brain barrier. As far as their chemical structure and solubility in water is concerned, 99m Tc-labelled tetracyclines occupy a position intermediate between the two comparative substances and the blood concentrations measured here were only moderately high. As they are accumulated to a considerable degree in the kidneys, the possibility of these substances' use in connection with renal scintiscans does not seem remote. In view of the fact that only one tenth of the dose of pertechnetate would be required for this purpose, radiation exposure could be reduced to a reasonable minimum. (TRV) [de

  20. Effects of tetracycline administration on the proteomic profile of pig muscle samples (L. dorsi)

    DEFF Research Database (Denmark)

    Gratacos-Cubarsi, M.; Castellari, M.; Hortos, M.

    2008-01-01

    Effect of tetracycline (TC) administration on the proteomic profile of pig muscle was evaluated by 2D electrophoresis and MALDI-TOF mass spectrometry. The TC content at slaughter was determined in L. dorsi samples by HPLC-DAD. Mean residual concentration of TC in the muscle of treated animals, ca...

  1. Safety mechanism assisted by the repressor of tetracycline (SMART) vaccinia virus vectors for vaccines and therapeutics.

    Science.gov (United States)

    Grigg, Patricia; Titong, Allison; Jones, Leslie A; Yilma, Tilahun D; Verardi, Paulo H

    2013-09-17

    Replication-competent viruses, such as Vaccinia virus (VACV), are powerful tools for the development of oncolytic viral therapies and elicit superior immune responses when used as vaccine and immunotherapeutic vectors. However, severe complications from uncontrolled viral replication can occur, particularly in immunocompromised individuals or in those with other predisposing conditions. VACVs constitutively expressing interferon-γ (IFN-γ) replicate in cell culture indistinguishably from control viruses; however, they replicate in vivo to low or undetectable levels, and are rapidly cleared even in immunodeficient animals. In an effort to develop safe and highly effective replication-competent VACV vectors, we established a system to inducibly express IFN-γ. Our SMART (safety mechanism assisted by the repressor of tetracycline) vectors are designed to express the tetracycline repressor under a constitutive VACV promoter and IFN-γ under engineered tetracycline-inducible promoters. Immunodeficient SCID mice inoculated with VACVs not expressing IFN-γ demonstrated severe weight loss, whereas those given VACVs expressing IFN-γ under constitutive VACV promoters showed no signs of infection. Most importantly, mice inoculated with a VACV expressing the IFN-γ gene under an inducible promoter remained healthy in the presence of doxycycline, but exhibited severe weight loss in the absence of doxycycline. In this study, we developed a safety mechanism for VACV based on the conditional expression of IFN-γ under a tightly controlled tetracycline-inducible VACV promoter for use in vaccines and oncolytic cancer therapies.

  2. Removal of tetracycline from contaminated water by Moringa oleifera seed preparations.

    Science.gov (United States)

    Santos, Andréa F S; Matos, Maria; Sousa, Ângela; Costa, Cátia; Nogueira, Regina; Teixeira, José A; Paiva, Patrícia M G; Parpot, Pier; Coelho, Luana C B B; Brito, António G

    2016-01-01

    The aim of this study was to evaluate tetracycline antibiotic (TA) removal from contaminated water by Moringa oleifera seed preparations. The composition of synthetic water approximate river natural contaminated water and TA simulated its presence as an emerging pollutant. Interactions between TA and protein preparations (extract; fraction and lectin) were also evaluated. TA was determined by solid-phase extraction followed by high-performance liquid chromatography-mass spectrometry. Moringa extract and flour removed TA from water. The extract removed TA in all concentrations, and better removal (40%) was obtained with 40 mg L(-1); seed flour (particles  5 mm (0.50 g L(-1)) removed 55% of antibiotic. Interactions between TA and seed preparations were assayed by haemagglutinating activity (HA). Specific HA (SHA) of extract (pH 7) was abolished with tetracycline (5 mg L(-1)); fraction (75%) and lectin HA (97%) were inhibited with TA. Extract SHA decreased by 75% at pH 8. Zeta potential (ZP) of extract 700 mg L(-1) and tetracycline 50 mg L(-1) , pH range 5-8, showed different results. Extract ZP was more negative (-10.73 to -16.00 mV) than tetracycline ZP (-0.27 to -20.15 mV); ZP difference was greater in pH 8. The focus of this study was achieved since Moringa preparations removed TA from water and compounds interacting with tetracycline involved at least lectin-binding sites. This is a natural process, which do not promote environmental damage.

  3. Protective effect of bicyclol on tetracycline-induced fatty liver in mice

    International Nuclear Information System (INIS)

    Yu, Hong-Yan; Wang, Bao-Lian; Zhao, Jing; Yao, Xiao-Min; Gu, Yu; Li, Yan

    2009-01-01

    Peroxisome proliferators-activated receptor α (PPARα) and oxidative stress are two important pathological factors in non-alcoholic fatty liver disease (NAFLD). Tetracycline-induced fatty liver was partly due to the disturbance of mitochondrial fatty acids β-oxidation regulated by PPARα. Bicyclol was found to protect against high fat diet-induced fatty liver through modulating PPARα and clearing reactive oxygen species (ROS). The present study was performed to further investigate the effect of bicyclol on tetracycline-induced fatty liver and related mechanism in mice. Bicyclol (75, 150, 300 mg/kg) was given orally three times in two consecutive days. Tetracycline (200 mg/kg) was injected intraperitoneally 1 h after the last administration of bicyclol. Oxidative stress, mitochondrial function, PPARα and its target genes were evaluated by biochemical and RT-PCR analysis. The activity of CYP4A was assessed by liquid chromatography/mass spectrometry (LC/MS) method. Bicyclol significantly protected against tetracycline-induced fatty liver by reducing the accumulation of hepatic lipids and elevation of serum aminotransferase. In addition, bicyclol remarkably alleviated the over-production of thiobarbituric acid-reactive substance. The reduced activity of mitochondrial respiratory chain (MRC) complexes I and IV and mitochondrial permeability transition (MPT) were also improved by bicyclol. Furthermore, bicyclol inhibited the decrease of PPARα expression and its target genes, including long-chain acyl CoA dehydrogenase (LCAD), acetyl CoA oxidase (AOX) and CYP4A at mRNA and enzyme activity level. Bicyclol protected against tetracycline-induced fatty liver mainly through modulating the disturbance of PPARα pathway and ameliorating mitochondrial function.

  4. TiO{sub 2}–graphene sponge for the removal of tetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lianqin [Southwest University for Nationalities, College of Chemistry and Environment Protection Engineering (China); Xue, Fumin [Shandong Academy of Science, Shandong Provincial Analysis and Tester Center (China); Yu, Baowei; Xie, Jingru; Zhang, Xiaoliang; Wu, Ruihan; Wang, Ruijue; Hu, Zhiyan; Yang, Sheng-Tao, E-mail: yangst@pku.edu.cn; Luo, Jianbin, E-mail: luojb1971@163.com [Southwest University for Nationalities, College of Chemistry and Environment Protection Engineering (China)

    2015-01-15

    Spongy graphene adsorbents have attracted great research interest recently, because of the high adsorption capacity, easy handling, and low operating cost. Fabrication of graphene sponge with other high-performance adsorbents might combine the merits of both materials, thus deserves more investigations. In this study, TiO{sub 2}–graphene sponge (TiO{sub 2}–GS) was prepared by the deposition of amorphous TiO{sub 2} on graphene oxide (GO) sheets for the adsorption of tetracycline antibiotics, where lyophilization was adopted to obtain the porous structure. TiO{sub 2}–GS adsorbed tetracycline with a large adsorption capacity of 1,805 mg/g, larger than that of GO (313 mg/g) and GO-chitosan aerogel (1,470 mg/g). The adsorption kinetics, which finally reached the equilibrium at 48 h, was clearly controlled by the diffusion of tetracycline to TiO{sub 2}–GS in the initial stage according to intraparticle diffusion model. Thermodynamics investigation indicated that the adsorption process was endothermic and promoted at higher temperature, with a positive ΔH of 35.8 kJ/mol. Generally, higher pH facilitated the adsorption of tetracycline on TiO{sub 2}–GS, except that the adsorption was also very effective at pH 1. In contrast, ionic strength had insignificant influence. The adsorbed tetracycline could be washed out with acidic ice-cold water to regenerate TiO{sub 2}–GS. The implication to the applications of TiO{sub 2}–GS in water treatment is discussed.

  5. Uso indiscriminado de tetraciclinas en afecciones bucales de origen odontógenas Overuse of tetracycline in oral diseases of odontogenous origin

    Directory of Open Access Journals (Sweden)

    Hilda Rodríguez Chala

    2007-03-01

    Full Text Available El uso de los antibióticos en la terapéutica de las enfermedades infecciosas constituyó un avance en la historia de la humanidad. Sin embargo, en la actualidad existe un uso indiscriminado de estos, que trae consigo la resistencia bacteriana y por ende, la no efectividad del mismo. Se realizó un estudio en 40 pacientes que ingerían la tetraciclina debido a afecciones bucales de origen odontógeno, con el objetivo de conocer cuáles eran las enfermedades bucales donde esta se utilizaba indiscriminadamente, así como los mecanismos (automedicación o prescripción. Se obtuvieron comos resultados que las odontalgias por alteraciones pulpares y los abscesos dentoalveolares agudos son las patologías bucales donde se usa irracionalmente la tetraciclina, tanto en el fenómeno de automedicación como en la prescripción por parte de facultativos. La automedicación fue la vía dónde se evidenció mayor uso de la tetraciclina con el 67,5 %, y se observaron varios factores que condicionan este comportamiento. Existió un elevado porcentaje de no efectividad de este ante afecciones bucales debido al uso indiscriminado, ya sea por no ser el antibiótico de elección ante la patología o por ser ingerido innecesariamente.The use of antibiotics in treating infectious diseases was a breakthrough in the history of mankind. However, there is at present an excessive use of these drugs that leads to antimicrobial resistance and ineffectiveness. Forty patients, who took tetracycline for oral diseases of odontogenous origin, were studied to find out the oral diseases where this drug was overused as well as the intake mechanisms (self-medication or prescription. The achieved results showed that odontalgias from pulpar disturbances and acute dentoalveolary abscesses are the oral pathologies where tetracycline is irrationally overused through self-medication and prescription by physicians. Self-medication was the most frequent way of administering tetracycline

  6. Characterization of resistance mechanisms and genetic relatedness of carbapenem-resistant Acinetobacter baumannii isolated from blood, Italy.

    Science.gov (United States)

    Migliavacca, Roberta; Espinal, Paula; Principe, Luigi; Drago, Monica; Fugazza, Giulia; Roca, Ignasi; Nucleo, Elisabetta; Bracco, Silvia; Vila, Jordi; Pagani, Laura; Luzzaro, Francesco

    2013-02-01

    The aim of this study was to characterize the resistance mechanisms and genetic relatedness of 21 carbapenem-resistant Acinetobacter baumannii blood isolates collected in Italy during a 1-year multicenter prospective surveillance study. Genes coding for carbapenemase production were identified by polymerase chain reaction (PCR) and sequencing. Pulsed-field gel electrophoresis (PFGE), multiplex PCRs for group identification, and multilocus sequence typing (MLST) were used to determine genetic relationships. Carbapenem resistance was consistently related to the production of oxacillinases, mostly the plasmid-mediated OXA-58 enzyme. Strains producing the OXA-23 enzyme (chromosomally mediated) were also detected. Seven PFGE clones were identified, some of which being related to international (ICL- I and ICL-II) or national clonal lineages. Multiplex PCRs identified 4 different groups (group 2 being dominant), further distinguishable in 6 sequence types by MLST. The heterogeneity of profiles highlights the diffusion of international and national clonal lineages in Italy. Continuous surveillance is needed for monitoring the spread of these worrisome strains equipped with multiple drug resistance mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Bicyclol attenuates tetracycline-induced fatty liver associated with inhibition of hepatic ER stress and apoptosis in mice.

    Science.gov (United States)

    Yao, Xiao-Min; Li, Yue; Li, Hong-Wei; Cheng, Xiao-Yan; Lin, Ai-Bin; Qu, Jun-Ge

    2016-01-01

    Endoplasmic reticulum (ER) stress is known to be involved in the development of several metabolic disorders, including non-alcoholic fatty liver disease (NAFLD). Tetracycline can cause hepatic steatosis, and ER stress may be involved in tetracycline-induced fatty liver. Our previous study showed that bicyclol has been proven to protect against tetracycline-induced fatty liver in mice, and ER stress may also be involved in bicyclol's hepatoprotective effect. Therefore, this study was performed to investigate the underlying mechanisms associated with ER stress and apoptosis, by which bicyclol attenuated tetracycline-induced fatty liver in mice. Bicyclol (300 mg/kg) was given to mice by gavage 3 times. Tetracycline (200 mg/kg, intraperitoneally) was injected at 1 h after the last dose of bicyclol. At 6 h and 24 h after single dose of tetracycline injection, serum ALT, AST, TG, CHO and hepatic histopathological examinations were performed to evaluate liver injuries. Hepatic steatosis was assessed by the accumulation of hepatic TG and CHO. Moreover, hepatic apoptosis and ER stress related markers were determined by TUNEL, real-time PCR, and western blot. As a result, bicyclol significantly protected against tetracycline-induced fatty liver as evidenced by the decrease of elevated serum transaminases and hepatic triglyceride, and the attenuation of histopathological changes in mice. In addition, bicyclol remarkably alleviated hepatic apoptosis and the gene expression of caspase-3, and increased the gene expression of XIAP. The gene expressions of ER stress-related markers, including CHOP, GRP78, IRE-1α, and ATF6, which were downregulated by bicyclol pretreatment in tetracycline-injected mice. These results suggested that bicyclol protected tetracycline-induced fatty liver partly due to its ability of anti-apoptosis associated with ER stress.

  8. The association between measurements of antimicrobial use and resistance in the faeces microbiota of finisher batches.

    Science.gov (United States)

    Andersen, V D; DE Knegt, L V; Munk, P; Jensen, M S; Agersø, Y; Aarestrup, F M; Vigre, H

    2017-10-01

    The objectives were to present three approaches for calculating antimicrobial (AM) use in pigs that take into account the rearing period and rearing site, and to study the association between these measurements and phenotypical resistance and abundance of resistance genes in faeces samples from 10 finisher batches. The AM use was calculated relative to the rearing period of the batches as (i) 'Finisher Unit Exposure' at unit level, (ii) 'Lifetime Exposure' at batch level and (iii) 'Herd Exposure' at herd level. A significant effect on the occurrence of tetracycline resistance measured by cultivation was identified for Lifetime Exposure for the AM class: tetracycline. Furthermore, for Lifetime Exposure for the AM classes: macrolide, broad-spectrum penicillin, sulfonamide and tetracycline use as well as Herd Unit Exposure for the AM classes: aminoglycoside, lincosamide and tetracycline use, a significant effect was observed on the occurrence of genes coding for the AM resistance classes: aminoglycoside, lincosamide, macrolide, β-lactam, sulfonamide and tetracycline. No effect was observed for Finisher Unit Exposure. Overall, the study shows that Lifetime Exposure is an efficient measurement of AM use in finisher batches, and has a significant effect on the occurrence of resistance, measured either by cultivation or metagenomics.

  9. Electrochemical oxidation of tetracycline antibiotics using a Ti/IrO2 anode for wastewater treatment of animal husbandry.

    Science.gov (United States)

    Miyata, M; Ihara, I; Yoshid, G; Toyod, K; Umetsu, K

    2011-01-01

    In animal husbandry, antibiotics are widely used to treat and prevent diseases or to promote growth. The use of antibiotics for domestic animals enables to promote safety of livestock products and enhance productivity. Tetracycline antibiotics (TCs) are one of the primarily used groups of antibiotics for cattle and swine. However, the unintentional spreading of antibiotics from animal waste to the environment may leave out drug residues, promoting resistant strains of bacteria, and will adversely affect the ecosystem and human health. To prevent the spread of veterinary antibiotics in the environment, it is required to treat residual antibiotics in livestock wastewater. In this study, we investigated the electrochemical oxidation of TCs to treat livestock wastewater. The concentrations of TCs in aqueous solutions were reduced from 100 mg/L to less than 0.6 mg/L by 6 h of electrochemical treatment using a Ti/IrO2 anode with Na2SO4 electrolyte. The concentration of oxytetracycline (OTC) in livestock wastewater was also reduced from 100 mg/L to less than 0.7 mg/L by the same treatment. Thus, the electrochemical oxidation using a Ti/IrO2 anode with Na2SO4 electrolyte was found to be effective for degradation of TCs. The results suggest that the electrochemical oxidation method is a promising treatment for TCs in livestock wastewater.

  10. Effects of in-feed chlortetracycline prophylaxis of beef cattle on animal health and antimicrobial-resistant Escherichia coli

    Science.gov (United States)

    Concerns have been raised that in-feed chlortetracycline (CTC) may increase antimicrobial resistance (AMR), specifically tetracycline-resistant (TETr) Escherichia coli, and third-generation cephalosporin-resistant (3GCr) E. coli. We evaluated the impact of a 5-day in-feed CTC prophylaxis on animal h...

  11. Polymyxin susceptibility testing, interpretative breakpoints and resistance mechanisms: An update.

    Science.gov (United States)

    Bakthavatchalam, Yamuna Devi; Pragasam, Agila Kumari; Biswas, Indranil; Veeraraghavan, Balaji

    2018-03-01

    Emerging multidrug-resistant (MDR) nosocomial pathogens are a great threat. Polymyxins, an old class of cationic polypeptide antibiotic, are considered as last-resort drugs in treating infections caused by MDR Gram-negative bacteria. Increased use of polymyxins in treating critically ill patients necessitates routine polymyxin susceptibility testing. However, susceptibility testing both of colistin and polymyxin B (PMB) is challenging. In this review, currently available susceptibility testing methods are briefly discussed. The multicomponent composition of colistin and PMB significantly influences susceptibility testing. In addition, poor diffusion in the agar medium, adsorption to microtitre plates and the synergistic effect of the surfactant polysorbate 80 with polymyxins have a great impact on the performance of susceptibility testing methods This review also describes recently identified chromosomal resistance mechanisms, including modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose (L-Ara4-N) and phosphoethanolamine (pEtN) resulting in alteration of the negative charge, as well as the plasmid-mediated colistin resistance determinants mcr-1, mcr-1.2, mcr-2 and mcr-3. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  12. Dissemination of antibiotic resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant S aureus strains isolated from hospital effluents.

    Science.gov (United States)

    Mandal, Santi M; Ghosh, Ananta K; Pati, Bikas R

    2015-12-01

    Vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant S aureus (MRSA) strains were examined in hospital effluents. Most S aureus strains are resistant to methicillin (MRSA), followed by tetracycline. Approximately 15% of MRSA strains are also resistant to vancomycin (VRSA). All VRSA strains developed a VanR/VanS-regulated 2-component system of VanA-type resistance in their genome. Results indicate that there is a possibility of developing resistance to aminoglycosides by VRSA strains in the near future. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  13. Antimicrobial resistance in Salmonella spp. recovered from patients admitted to six different hospitals in Tehran, Iran from 2007 to 2008

    DEFF Research Database (Denmark)

    Tajbakhsh, Mercedeh; Hendriksen, Rene S.; Nochi, Zahra

    2012-01-01

    were screened for the presence of Salmonella, serotyped, tested for antimicrobial susceptibility using disk diffusion and examined for the presence of relevant resistance genes and integrons by PCR. A total of 1,120 patients were screened for the presence of Salmonella. Out of 71 Salmonella isolates...... recovered, the following serovars were identified: 17 Typhi, 14 Paratyphi C, 13 Enteritidis, 11 Paratyphi B, 10 Paratyphi A and six Infantis. Most resistance was observed towards sulfamethoxazole (30%), tetracyclines (25%), nalidixic acid (22%), spectinomycin (17%), trimethoprim (15%), ampicillin (14......%) and kanamycin (14%). The tetracycline resistance genes tet(A), tet(B), and tet(G) were found in 28%, 14% and 6% of the tetracycline resistant isolates, respectively. The genes aadA, aadB, strA, strB and aphA1-Iab were present in 83%, 55%, 34%, 1% and 17% of the aminoglycoside resistant isolates, respectively...

  14. Tetracycline treatment of type III prostatitis nanobacteria infection of 100 cases report

    Science.gov (United States)

    Guo, Junyi; Li, Chongxian; Wu, Baisuo; Hao, Shaojun; Ming, Aimin; Zhang, Xinji; Li, Wenjun; Zhang, Zhengchen

    2018-04-01

    To investigate the efficacy of tetracycline treatment of nanobacterial infection in 100 cases of type III prostatitis. randomly divided into treatment group and control group with double blind method, the treatment group was given Tetracycline Tablets 250mg, oral, 2 times a day; the control group were treated with Levofloxacin Tablets 0.lg, oral, 2 times a day; observation of curative effect of two groups of patients after 1 months of treatment. after the treatment group patients NIH-CPSI score and pain, urinary symptoms and quality of life scores were significantly lower than that of control group (Pprostate fluid and cultured positive cases of nanobacterial numbers were 21 (21%) and 100 cases (100%), the positive rate of nanobacteria in observation group was significantly lower than the control group (Pprostatitis.

  15. Use of computational modeling in preparation and evaluation of surface imprinted xerogels for binding tetracycline

    International Nuclear Information System (INIS)

    Pace, Samantha J.; Nguyen, Eric; Baria, Maximillian P.; Mojica, Elmer-Rico E.

    2015-01-01

    Linear alkyl alkoxysilanes (methoxy and ethoxy-based) of varying length were used in preparing tetracycline surface imprinted silica xerogels by the sol–gel process. The resulting xerogels were characterized in terms of binding tetracycline (TC) by using tritium-labeled TC. Results showed preferential binding in the ethoxysilane based xerogels in comparison to methoxysilane based xerogels. A computational approach using the interaction energy (IE) between TC and each alkyl alkoxysilane was deduced as a rational way of predicting the formulation that would provide the best analytical performance for a given molecularly imprinted xerogel (MIX). Hartree-Fock calculations revealed an increase in IE as the length of the carbon chain increases until an optimum value at C6 in both alkoxysilanes. This is consistent with the experimental results wherein the C6 xerogel formulation has the highest imprinting factor. These results show the potential of using computational modeling as a rational way of preparing surface imprinted materials. (author)

  16. On the protection of E.coli against radiation lethality by ascorbate combined with tetracycline

    International Nuclear Information System (INIS)

    Djalali-Behzad, G.; Ehrenberg, L.

    1977-01-01

    The radioprotective action in E.coli ATCC 9637 of ascorbate added to media containing the weak sensitizer, tetracycline (Pittillo, R.F., and Lucas, M.B., 1967, Radiat. Res., vol. 31, 36) was found to be dependent on the presence of metal catalysts of the autoxidation of ascorbate. Thus, the protective action of ascorbate + tetracycline as well as the rate of autoxidation of ascorbate in this mixture were enhanced by 0.1 μM Cu, and these effects were counteracted by pyrophosphate probably through chelation of iron that contaminates phosphate. A suppression of metabolism is apparently involved in the combined action as judged by the decrease of incorporation of labelled uridine. (author)

  17. Simultaneous determination of five tetracycline and macrolide antibiotics in feeds using HPCE.

    Science.gov (United States)

    Tong, Jing; Rao, Qinxiong; Zhu, Kui; Jiang, Zhigang; Ding, Shuangyang

    2009-12-01

    This work demonstrates the potential of HPCE in the analysis of antibiotics in a complex matrix such as feedstuffs. Using 20 mM citric acid-40 mM Na(2)HPO(4) buffer (pH 2.65), the five antibiotics, tetracycline, oxytetracycline, doxycycline, tilmicosin, and tylosin were successfully separated at 30 kV in a 64.5 cm x 75 microm id capillary. Good repeatability, stability, and reliability of the method were supported by 70%, and the limit of detection of the five analytes was 0.5-1 mg/kg. It was for the first time that a capillary electrophoretic method was employed to simultaneously detect five tetracycline and macrolide antibiotics in animal feeds.

  18. Organ distribution of sup(99m)Tc-Sn tetracycline antibiotics in rats

    International Nuclear Information System (INIS)

    Kalincak, M.; Machan, V.; Barna, K.

    1976-01-01

    The organ distribution of [sup(99m)Tc-Sn]tetracycline hydrochloride, [sup(99m)Tc-Sn]oxytetracycline hydrochloride and [sup(99m)Tc-Sn]rolitetracycline nitrate was studied in rats. It was shown that these preparations have a very similar organ distribution and are predominantly deposited in the kidneys. The maximum renal radioactivity level was found 2 to 4 hours after intravenous administration of the preparation, this, for [sup(99m)Tc-Sn]tetracycline hydrochloride 18.60%; for [sup(99m)Tc-Sn]oxytetracycline hydrochloride 17.09.=.; for [sup(99m)Tc-Sn]rolitetracycline nitrate 20.12%. The activity levels in the muscle, liver, heart, brain, lungs, stomach and spleen are minimal. (author)

  19. Organ distribution of /sup 99m/Tc--Sn tetracycline antibiotics in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kalincak, M; Machan, V; Barna, K [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Lekarska Fakulta

    1976-06-01

    The organ distribution of (sup(99m)Tc-Sn)tetracycline hydrochloride, (sup(99m)Tc-Sn)oxytetracycline hydrochloride and (sup(99m)Tc-Sn)rolitetracycline nitrate was studied in rats. It was shown that these preparations have a very similar organ distribution and are predominantly deposited in the kidneys. The maximum renal radioactivity level was found 2 to 4 hours after intravenous administration of the preparation, this, for (sup(99m)Tc-Sn)tetracycline hydrochloride 18.60%; for (sup(99m)Tc-Sn)oxytetracycline hydrochloride 17.09.=.; for (sup(99m)Tc-Sn)rolitetracycline nitrate 20.12%. The activity levels in the muscle, liver, heart, brain, lungs, stomach and spleen are minimal.

  20. Efficacy of chloramphenicol, enrofloxacin, and tetracycline for treatment of experimental Rocky Mountain spotted fever in dogs.

    Science.gov (United States)

    Breitschwerdt, E B; Davidson, M G; Aucoin, D P; Levy, M G; Szabados, N S; Hegarty, B C; Kuehne, A L; James, R L

    1991-01-01

    Dogs were experimentally inoculated with Rickettsia rickettsii to characterize the comparative efficacies of chloramphenicol, enrofloxacin, and tetracycline for the treatment of Rocky Mountain spotted fever (RMSF). All three antibiotics were equally effective in abrogating the clinical, hematologic, and vascular indicators of rickettsial infection. Antibiotic treatment for 24 h was sufficient to decrease the rickettsemia to levels below detection by Vero cell culture. Early treatment with all three antibiotics resulted in a similar decrease in antibody titer, but acute and convalescent serum samples taken at appropriate times would have still facilitated an accurate diagnosis of RMSF in all but one dog, which did not seroconvert. We conclude that chloramphenicol, enrofloxacin, and tetracycline are equally efficacious for treating experimental canine RMSF. PMID:1666498

  1. Protection of E. coli against radiation lethality by ascorbate combined with tetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Djalali-Behzad, G; Ehrenberg, L [Stockholm Univ. (Sweden). Radiobiologiska Institutionen

    1977-06-01

    The radioprotective action in E.coli ATCC 9637 of ascorbate added to media containing the weak sensitizer, tetracycline (Pittillo, R.F., and Lucas, M.B., 1967, Radiat. Res., vol. 31, 36) was found to be dependent on the presence of metal catalysts of the autoxidation of ascorbate. Thus, the protective action of ascorbate + tetracycline as well as the rate of autoxidation of ascorbate in this mixture were enhanced by 0.1 ..mu..M Cu, and these effects were counteracted by pyrophosphate probably through chelation of iron that contaminates phosphate. A suppression of metabolism is apparently involved in the combined action as judged by the decrease of incorporation of labelled uridine.

  2. Pharmacodynamic modelling of in vitro activity of tetracycline against a representative, naturally occurring population of porcine Escherichia coli

    DEFF Research Database (Denmark)

    Ahmad, Amais; Zachariasen, Camilla; Christiansen, Lasse Engbo

    2015-01-01

    The complex relationship between drug concentrations and bacterial growth rates require not only the minimum inhibitory concentration but also other parameters to capture the dynamic nature of the relationship. To analyse this relationship between tetracycline concentration and growth of Escheric...

  3. Defining the Relationship Between Phenotypic and Genotypic Resistance Profiles of Multidrug-Resistant Enterobacterial Clinical Isolates.

    Science.gov (United States)

    Galal, Lamis; Abdel Aziz, Neveen A; Hassan, Walaa M

    2018-05-11

    Fluoroquinolones and aminoglycosides offer effective therapy for extended-spectrum beta-lactamase (ESBL)-producing enterobacterial infections, but their usefulness is threatened by increasing resistant strains. This study was conducted to demonstrate the phenotypic outcomes of the coexistence of genetic determinants mediating resistance to extended-spectrum cephalosporins and quinolones in enterobacterial isolates collected from patients with health-care-associated infections in Egypt. ESBL phenotype was determined using double-disk synergy test (DDST). The PCR technique was used to detect the presence of the genes mediating quinolone resistance (qnr and aac(6')-Ib-cr) and coexistence with ESBL genes. We also examined the association between the genetic makeup of the isolates and their resistance profiles including effect on MIC results. Phenotypically ESBLs were detected in 60-82% of the enterobacterial isolates. ESBL, qnr and aac(6')-Ib-cr genes were detected with the following percentages in Citrobacter isolates (69%, 69%, and 43%, respectively), E.coli isolates (65%, 70%, and 45%, respectively), Enterobacter isolates (56%, 67%, and 33%, respectively), and finally Klebsiella isolates (42%, 66%, and 25%, respectively). The coexistence of these multiresistant genetic elements significantly increased the MIC values of the tested antibiotics from different classes. We suggest using blaTEM, blaCTX-M-15, qnr, and aac(6')-Ib-cr genes for better and faster prediction of suitable antibiotic therapy with effective doses against ESBL-producing isolates harboring plasmid-mediated quinolone resistance (PMQR) determinants. Amikacin, meropenem, gentamicin, and imipenem seem to be better choices of treatment for such life-threatening infections, because of their remaining highest activity.

  4. Investigation of plasmid DNA and antibiotic resistance in some ...

    African Journals Online (AJOL)

    Twenty-eight strains of Salmonella, Pseudomonas, and Escherichia coli isolated from cultures of stool, urine and wound were tested for their susceptibility to various antimicrobial agents. All the strains were resistant to erythromycin and tetracycline. Nineteen Salmonella isolates were susceptible to chloramphenicol and ...

  5. Electrochemical oxidation of drug residues in water by the example of tetracycline, gentamicin and Aspirin {sup trademark}

    Energy Technology Data Exchange (ETDEWEB)

    Weichgrebe, D.; Danilova, E.; Rosenwinkel, K.H. [Inst. of Water Quality and Waste Management, Univ. of Hannover, Hannover (Germany); Vedenjapin, A.; Baturova, M. [Inst. of Organic Chemistry, Russian Academy of Science, Moscow (Russian Federation)

    2003-07-01

    The electrochemical oxidation as a method to destroy drug residues like Aspirin {sup trademark}, tetracycline or gentamicin in water was investigated with C-Anode (modified by manganese oxides) and Pt Anode. The mechanism of Aspirin {sup trademark} and tetracycline oxidation and the influence of the biocide effect was observed using GC-MS and three different microbiological tests. In general the biological availability increases with progressive oxidation of the antibiotics. (orig.)

  6. Kinetics of tetracycline, oxytetracycline, and chlortetracycline adsorption and desorption on two acid soils.

    Science.gov (United States)

    Fernández-Calviño, David; Bermúdez-Couso, Alipio; Arias-Estévez, Manuel; Nóvoa-Muñoz, Juan Carlos; Fernández-Sanjurjo, Maria J; Álvarez-Rodríguez, Esperanza; Núñez-Delgado, Avelino

    2015-01-01

    The purpose of this work was to quantify retention/release of tetracycline, oxytetracycline, and chlortetracycline on two soils, paying attention to sorption kinetics and to implications of the adsorption/desorption processes on transfer of these pollutants to the various environmental compartments. We used the stirred flow chamber (SFC) procedure to achieve this goal. All three antibiotics showed high affinity for both soils, with greater adsorption intensity for soil 1, the one with the highest organic matter and Al and Fe oxides contents. Desorption was always  oxytetracycline > chlortetracycline in soil 1, with similar values for the three antibiotics and the sequence tetracycline > chlortetracycline > oxytetracycline in soil 2. The desorption sequences were oxytetracycline > tetracycline > chlortetracycline in soil 1 and oxytetracycline > chlortetracycline > tetracycline in soil 2. In conclusion, the SFC technique has yielded new kinetic data regarding tetracycline, oxytetracycline, and chlortetracycline adsorption/desorption on soils, indicating that it can be used to shed further light on the retention and transport processes affecting antibiotics on soils and other media, thus increasing knowledge on the behavior and evolution of these pharmaceutical residues in the environment.

  7. Hormetic effect(s) of tetracyclines as environmental contaminant on Zea mays

    International Nuclear Information System (INIS)

    Migliore, Luciana; Godeas, Feliciana; De Filippis, Stefania Paola; Mantovi, Paolo; Barchi, Davide; Testa, Cecilia; Rubattu, Nicolino; Brambilla, Gianfranco

    2010-01-01

    Animal wastes from intensive pig farming as fertilizers may expose crops to antimicrobials. Zea mays cultivations were carried out on a virgin field, subjected to dressing with pig slurries contaminated at 15 mg L -1 of Oxy- and 5 mg L -1 of Chlor-tetracycline, and at 8 mg L -1 of Oxy and 3 mg L -1 of Chlor, respectively. Pot cultivation was performed outdoor (Oxy in the range 62.5-1000 ng g -1 dry soil) and plants harvested after 45 days. Tetracyclines analyses on soils and on field plants (roots, stalks, and leaves) did not determine the appreciable presence of tetracyclines. Residues were found in the 45-day pot corn only, in the range of 1-50 ng g -1 for Oxy in roots, accounting for a 5% carry-over rate, on average. Although no detectable residues in plants from on land cultivations, both experimental batches showed the same biphasic growth form corresponding to a dose/response hormetic curve. - Oxytetracycline in soils elicits a hormetic response in Zea mays plants.

  8. Hormetic effect(s) of tetracyclines as environmental contaminant on Zea mays

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, Luciana; Godeas, Feliciana [Dipartimento di Biologia, Universita Tor Vergata, Rome (Italy); De Filippis, Stefania Paola [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy); Mantovi, Paolo [Centro Ricerche Produzioni Animali, Reggio Emilia (Italy); Barchi, Davide [Assessorato all' Agricoltura, Regione Emilia-Romagna, Bologna (Italy); Testa, Cecilia; Rubattu, Nicolino [Istituto Zooprofilattico Sperimentale della Sardegna, Sassari (Italy); Brambilla, Gianfranco [Istituto Superiore di Sanita, Toxicological Chemistry Unit, Rome (Italy)

    2010-01-15

    Animal wastes from intensive pig farming as fertilizers may expose crops to antimicrobials. Zea mays cultivations were carried out on a virgin field, subjected to dressing with pig slurries contaminated at 15 mg L{sup -1} of Oxy- and 5 mg L{sup -1} of Chlor-tetracycline, and at 8 mg L{sup -1} of Oxy and 3 mg L{sup -1} of Chlor, respectively. Pot cultivation was performed outdoor (Oxy in the range 62.5-1000 ng g{sup -1} dry soil) and plants harvested after 45 days. Tetracyclines analyses on soils and on field plants (roots, stalks, and leaves) did not determine the appreciable presence of tetracyclines. Residues were found in the 45-day pot corn only, in the range of 1-50 ng g{sup -1} for Oxy in roots, accounting for a 5% carry-over rate, on average. Although no detectable residues in plants from on land cultivations, both experimental batches showed the same biphasic growth form corresponding to a dose/response hormetic curve. - Oxytetracycline in soils elicits a hormetic response in Zea mays plants.

  9. Elimination patterns of worldwide used sulfonamides and tetracyclines during anaerobic fermentation.

    Science.gov (United States)

    Spielmeyer, Astrid; Breier, Bettina; Groißmeier, Kathrin; Hamscher, Gerd

    2015-10-01

    Antibiotics such as sulfonamides and tetracyclines are frequently used in veterinary medicine. Due to incomplete absorption in the animal gut and/or unmetabolized excretion, the substances can enter the environment by using manure as soil fertilizer. The anaerobic fermentation process of biogas plants is discussed as potential sink for antibiotic compounds. However, negative impacts of antibiotics on the fermentation process are suspected. The elimination of sulfadiazine, sulfamethazine, tetracycline and chlortetracycline in semi-continuous lab-scale fermenters was investigated. Both biogas production and methane yield were not negatively affected by concentrations up to 38 mg per kg for sulfonamides and 7 mg per kg for tetracyclines. All substances were partly eliminated with elimination rates between 14% and 89%. Both matrix and structure of the target molecule influenced the elimination rate. Chlortetracycline was mainly transformed into iso-chlortetracycline. In all other cases, the elimination pathways remained undiscovered; however, sorption processes seem to have a negligible impact. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Towards early detection of age-related macular degeneration with tetracyclines and FLIM

    Science.gov (United States)

    Szmacinski, Henryk; Hegde, Kavita; Zeng, Hui-Hui; Eslami, Katayoun; Puche, Adam; Lakowicz, Joseph R.; Lengyel, Imre; Thompson, Richard B.

    2018-02-01

    Recently, we discovered microscopic spherules of hydroxyapatite (HAP) in aged human sub-retinal pigment epithelial (sub-RPE) deposits in the retinas of aged humans (PMID: 25605911), and developed evidence that the spherules may act to nucleate the growth of sub-RPE deposits such as drusen. Drusen are clinical hallmarks of age-related macular degeneration (AMD). We found that tetracycline-family antibiotics, long known to stain HAP in teeth and bones, also stained the HAP spherules, but in general the HAP-bound fluorescence excitation and emission spectra overlapped with the well-known autofluorescence of the RPE overlying drusen, making them difficult to resolve. However, we also found that certain tetracyclines exhibited substantial increases in fluorescence lifetime upon binding to HAP, and moreover these lifetimes were substantially greater than those previously observed (Dysli, et al., 2014) for autofluorescence in the human retina in vivo. Thus we were able to image the HAP spherules by fluorescence lifetime imaging microscopy (FLIM) in cadaveric retinas of aged humans. These findings suggest that FLIM imaging of tetracycline binding to HAP could become a diagnostic tool for the development and progression of AMD.

  11. Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections

    Science.gov (United States)

    Sjölund-Karlsson, Maria; Gordon, Melita A.; Parry, Christopher M.

    2015-01-01

    SUMMARY Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015. PMID:26180063

  12. Effect of different oral oxytetracycline treatment regimes on selection of antimicrobial resistant coliforms in nursery pigs

    DEFF Research Database (Denmark)

    Fresno, Ana Herrero; Zachariasen, Camilla; Norholm, Nanna

    2017-01-01

    A major concern derived from using antimicrobials in pig production is the development of resistance. This study aimed to assess the impact of selected combinations of oral dose and duration of treatment with oxytetracycline (OTC) on selection of tetracycline resistant (TET-R) coliforms recovered...

  13. Relationship between trans-generational effects of tetracycline on Daphnia magna at the physiological and whole organism level

    International Nuclear Information System (INIS)

    Kim, Hyun Young; Yu, Seungho; Jeong, Tae-yong; Kim, Sang Don

    2014-01-01

    The effects of pharmaceuticals have been underestimated during single generation exposure. Therefore, in this study, we investigated toxic responses at the physiological and whole organism level in tetracycline-exposed Daphnia magna over four consecutive generational lifecycles. The results showed that tetracycline affected energy-related physiological functions in concentration- and generation-dependent manners, and especially maintenance costs increased. Consequently, multigenerational exposure to tetracycline induced changes in energy balance, resulting in the change of higher levels of biological responses. In contrast, D. magna acclimated to tetracycline exposure over multiple generations, as evidenced by the increased LC 50 values. Transgenerational adaptation was related to the neonatal sensitivity and energy reserves of the organism. The results also emphasized the idea that the number of generation is an important factor for toxicity. The present study confirmed that toxic stress induces metabolic changes in an organism, thereby leading to increased energy consumption that results in adverse effects on reproduction. - Highlights: • Transgenerational adaptation of D. magna to tetracycline was observed. • TCN affected energy-related physiological function and increased maintenance energy. • LC 50 value of TCN increased with increasing concentration and generation. • The number of exposure generation may be an important factor for toxicity. - The change in internal energy balance in daphnids during multigenerational exposure to tetracycline may explain whole organism responses

  14. Spectroscopic studies of europium-tetracyclines complexes and their applications in detection of hydrogen peroxide and urea peroxide

    International Nuclear Information System (INIS)

    Grasso, Andrea Nastri

    2010-01-01

    In this work were studied the spectroscopic properties of trivalent europium ion complexed with components of tetracycline family, chlorotetracycline, oxytetracycline and metacycline, in the presence of hydrogen peroxide and urea peroxide. Optical parameters were obtained such as absorption, emission, lifetime and calibration curves were constructed for luminescence spectra. Experiments were carried out with both inorganic compounds and europium-tetracyclines complexes in order to verify possible interferences. Studies for glucose determination were also described using europium-tetracyclines complexes as biosensors. Results show that europium tetracyclines complexes emit a narrow band in the visible region and, in the presence of hydrogen peroxide or urea peroxide there is a greater enhancement in their luminescence and lifetime. Thus, europium-tetracyclines complexes studied can be used as biosensors for hydrogen and urea peroxides determination as a low cost and room temperature method. An indirect method for glucose determination was studied by adding glucose oxidase enzyme in europium-tetracyclines complex in the presence of glucose promoting as product hydrogen peroxide. (author)

  15. Genetic markers associated with resistance to beta-lactam and quinolone antimicrobials in non-typhoidal Salmonella isolates from humans and animals in central Ethiopia

    Directory of Open Access Journals (Sweden)

    Tadesse Eguale

    2017-01-01

    Full Text Available Abstract Background Beta-lactam and quinolone antimicrobials are commonly used for treatment of infections caused by non-typhoidal Salmonella (NTS and other pathogens. Resistance to these classes of antimicrobials has increased significantly in the recent years. However, little is known on the genetic basis of resistance to these drugs in Salmonella isolates from Ethiopia. Methods Salmonella isolates with reduced susceptibility to beta-lactams (n = 43 were tested for genes encoding for beta-lactamase enzymes, and those resistant to quinolones (n = 29 for mutations in the quinolone resistance determining region (QRDR as well as plasmid mediated quinolone resistance (PMQR genes using PCR and sequencing. Results Beta-lactamase genes (bla were detected in 34 (79.1% of the isolates. The dominant bla gene was blaTEM, recovered from 33 (76.7% of the isolates, majority being TEM-1 (24, 72.7% followed by TEM-57, (10, 30.3%. The blaOXA-10 and blaCTX-M-15 were detected only in a single S. Concord human isolate. Double substitutions in gyrA (Ser83-Phe + Asp87-Gly as well as parC (Thr57-Ser + Ser80-Ile subunits of the quinolone resistance determining region (QRDR were detected in all S. Kentucky isolates with high level resistance to both nalidixic acid and ciprofloxacin. Single amino acid substitutions, Ser83-Phe (n = 4 and Ser83-Tyr (n = 1 were also detected in the gyrA gene. An isolate of S. Miami susceptible to nalidixic acid but intermediately resistant to ciprofloxacin had Thr57-Ser and an additional novel mutation (Tyr83-Phe in the parC gene. Plasmid mediated quinolone resistance (PMQR genes investigated were not detected in any of the isolates. In some isolates with decreased susceptibility to ciprofloxacin and/or nalidixic acid, no mutations in QRDR or PMQR genes were detected. Over half of the quinolone resistant isolates in the current study 17 (58.6% were also resistant to at least one of the beta-lactam antimicrobials

  16. Direct screening of tetracyclines in water and bovine milk using room temperature phosphorescence detection

    International Nuclear Information System (INIS)

    Traviesa-Alvarez, J.M.; Costa-Fernandez, J.M.; Pereiro, R.; Sanz-Medel, A.

    2007-01-01

    A fast and simple flow-through optosensor was designed and characterized for the direct screening of four tetracycline (TCC) antibiotics (tetracycline, oxytetracycline, chlortetracycline and doxycycline) in water and bovine milk samples. The proposed optosensor provides rapid binary yes/no overall responses, being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The experimental set-up is based on a flow-injection manifold coupled on-line to a phosphorescence detector. Aliquots of the samples are pretreated with Eu(III) to form room temperature phosphorescent metal chelates and injected in the flow manifold. Those chelates are then on-line retained on a conventional flow-cell (packed with polymeric Amberlite XAD-4 particles) which is placed inside the cell holder of the phosphorimeter. After the emission is registered, the antibiotic-metal complexes are eluted from the packed resin with 1 M HCl (for milk samples a second regeneration step, using methanol, should be performed). A sample throughput of about 20 samples per hour was obtained. Optimum experimental conditions include a pH 9, a Eu(III) concentration of 2 x 10 -4 M and 8 mM sodium sulphite as chemical deoxygenant. The phosphorescence emitted by the europium-TCC complexes was measured at 394 and 617 nm for excitation and emission wavelengths, respectively. The unreliability region, given by the probability of false positives and false negatives, respectively (set at 5% in both cases) was in the range between 0.2 and 11.6 nM for detection of tetracyclines in water samples (at a cut-off level of 4 nM) and in the range between 165 and 238 nM for detection of tetracyclines in milk (cut-off level fixed at the normative EU level of 200 nM). Finally, the applicability of the proposed screening optosensor was tested for the reliable control of tetracyclines in contaminated and uncontaminated water and milk samples

  17. Direct screening of tetracyclines in water and bovine milk using room temperature phosphorescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Traviesa-Alvarez, J M [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Costa-Fernandez, J M [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Pereiro, R [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain); Sanz-Medel, A [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, c/Julian Claveria 8, 33006 Oviedo (Spain)

    2007-04-18

    A fast and simple flow-through optosensor was designed and characterized for the direct screening of four tetracycline (TCC) antibiotics (tetracycline, oxytetracycline, chlortetracycline and doxycycline) in water and bovine milk samples. The proposed optosensor provides rapid binary yes/no overall responses, being appropriate for the screening of this family of antibiotics above or below a pre-set concentration threshold. The experimental set-up is based on a flow-injection manifold coupled on-line to a phosphorescence detector. Aliquots of the samples are pretreated with Eu(III) to form room temperature phosphorescent metal chelates and injected in the flow manifold. Those chelates are then on-line retained on a conventional flow-cell (packed with polymeric Amberlite XAD-4 particles) which is placed inside the cell holder of the phosphorimeter. After the emission is registered, the antibiotic-metal complexes are eluted from the packed resin with 1 M HCl (for milk samples a second regeneration step, using methanol, should be performed). A sample throughput of about 20 samples per hour was obtained. Optimum experimental conditions include a pH 9, a Eu(III) concentration of 2 x 10{sup -4} M and 8 mM sodium sulphite as chemical deoxygenant. The phosphorescence emitted by the europium-TCC complexes was measured at 394 and 617 nm for excitation and emission wavelengths, respectively. The unreliability region, given by the probability of false positives and false negatives, respectively (set at 5% in both cases) was in the range between 0.2 and 11.6 nM for detection of tetracyclines in water samples (at a cut-off level of 4 nM) and in the range between 165 and 238 nM for detection of tetracyclines in milk (cut-off level fixed at the normative EU level of 200 nM). Finally, the applicability of the proposed screening optosensor was tested for the reliable control of tetracyclines in contaminated and uncontaminated water and milk samples.

  18. Ciprofloxacin-resistant Escherichia coli in Central Greece: mechanisms of resistance and molecular identification

    Directory of Open Access Journals (Sweden)

    Mavroidi Angeliki

    2012-12-01

    Full Text Available Abstract Background Fluoroquinolone resistant E. coli isolates, that are also resistant to other classes of antibiotics, is a significant challenge to antibiotic treatment and infection control policies. In Central Greece a significant increase of ciprofloxacin-resistant Escherichia coli has occurred during 2011, indicating the need for further analysis. Methods A total of 106 ciprofloxacin-resistant out of 505 E. coli isolates consecutively collected during an eight months period in a tertiary Greek hospital of Central Greece were studied. Antimicrobial susceptibility patterns and mechanisms of resistance to quinolones were assessed, whereas selected isolates were further characterized by multilocus sequence typing and β-lactamase content. Results Sequence analysis of the quinolone-resistance determining region of the gyrA and parC genes has revealed that 63% of the ciprofloxacin-resistant E. coli harbored a distinct amino acid substitution pattern (GyrA:S83L + D87N; ParC:S80I + E84V, while 34% and 3% carried the patterns GyrA:S83L + D87N; ParC:S80I and GyrA:S83L + D87N; ParC:S80I + E84G respectively. The aac (6’-1b-cr plasmid-mediated quinolone resistance determinant was also detected; none of the isolates was found to carry the qnrA, qnrB and qnrS. Genotyping of a subset of 35 selected ciprofloxacin-resistant E. coli by multilocus sequence typing has revealed the presence of nine sequence types; ST131 and ST410 were the most prevalent and were exclusively correlated with hospital and health care associated infections, while strains belonging to STs 393, 361 and 162 were associated with community acquired infections. The GyrA:S83L + D87N; ParC:S80I + E84V substitution pattern was found exclusively among ST131 ciprofloxacin-resistant E. coli. Extended-spectrum β-lactamase-positive ST131 ciprofloxacin-resistant isolates produced CTX-M-type enzymes; eight the CTX-M-15 and one the CTX-M-3 variant. CTX-M-1 like and KPC-2 enzymes were detected

  19. Increase in resistance to extended-spectrum cephalosporins in Salmonella isolated from retail chicken products in Japan.

    Science.gov (United States)

    Noda, Tamie; Murakami, Koichi; Etoh, Yoshiki; Okamoto, Fuyuki; Yatsuyanagi, Jun; Sera, Nobuyuki; Furuta, Munenori; Onozuka, Daisuke; Oda, Takahiro; Asai, Tetsuo; Fujimoto, Shuji

    2015-01-01

    Extended-spectrum β-lactamase (ESBL)-producing Salmonella are one of the most important public health problems in developed countries. ESBL-producing Salmonella strains have been isolated from humans in Asian countries neighboring Japan, along with strains harboring the plasmid-mediated extended-spectrum cephalosporin (ESC)-resistance gene, ampC (pAmpC). However, only a few studies have investigated the prevalence of ESC-resistant Salmonella in chicken products in Japan, which are the main vehicle of Salmonella transmission. The aim of this study was to investigate the prevalence of ESBL-producing, pAmpC-harboring, or carbapenem-resistant Salmonella in chicken products in Japan. In total, 355 out of 779 (45.6%) chicken product samples collected from 1996-2010 contained Salmonella, resulting in 378 distinct isolates. Of these isolates, 373 were tested for resistance to ESCs, cephamycins, or carbapenems. Isolates that showed resistance to one or more of these antimicrobials were then examined by PCR and DNA sequence analysis for the presence of the bla(CMY), bla(CTX-M), bla(TEM), and bla(SHV) resistance genes. Thirty-five resistant isolates were detected, including 26 isolates that contained pAmpC (bla(CMY-2)), and nine ESBL-producing isolates harboring bla(CTX-M) (n = 4, consisting of two bla(CTX-M-2) and two bla(CTX-M-15 genes)), bla(TEM) (n = 4, consisting of one bla(TEM-20) and three bla(TEM-52) genes), and bla(SHV) (n = 1, bla(SHV-12)). All pAmpC-harboring and ESBL-producing Salmonella isolates were obtained from samples collected after 2005, and the percentage of resistant isolates increased significantly from 0% in 2004 to 27.9% in 2010 (P for trend = 0.006). This increase was caused in part by an increase in the number of Salmonella enterica subsp. enterica serovar Infantis strains harboring an approximately 280-kb plasmid containing bla(CMY-2) in proximity to ISEcp1. The dissemination of ESC-resistant Salmonella containing plasmid-mediated bla(CMY-2) in

  20. Increase in resistance to extended-spectrum cephalosporins in Salmonella isolated from retail chicken products in Japan.

    Directory of Open Access Journals (Sweden)

    Tamie Noda

    Full Text Available Extended-spectrum β-lactamase (ESBL-producing Salmonella are one of the most important public health problems in developed countries. ESBL-producing Salmonella strains have been isolated from humans in Asian countries neighboring Japan, along with strains harboring the plasmid-mediated extended-spectrum cephalosporin (ESC-resistance gene, ampC (pAmpC. However, only a few studies have investigated the prevalence of ESC-resistant Salmonella in chicken products in Japan, which are the main vehicle of Salmonella transmission. The aim of this study was to investigate the prevalence of ESBL-producing, pAmpC-harboring, or carbapenem-resistant Salmonella in chicken products in Japan. In total, 355 out of 779 (45.6% chicken product samples collected from 1996-2010 contained Salmonella, resulting in 378 distinct isolates. Of these isolates, 373 were tested for resistance to ESCs, cephamycins, or carbapenems. Isolates that showed resistance to one or more of these antimicrobials were then examined by PCR and DNA sequence analysis for the presence of the bla(CMY, bla(CTX-M, bla(TEM, and bla(SHV resistance genes. Thirty-five resistant isolates were detected, including 26 isolates that contained pAmpC (bla(CMY-2, and nine ESBL-producing isolates harboring bla(CTX-M (n = 4, consisting of two bla(CTX-M-2 and two bla(CTX-M-15 genes, bla(TEM (n = 4, consisting of one bla(TEM-20 and three bla(TEM-52 genes, and bla(SHV (n = 1, bla(SHV-12. All pAmpC-harboring and ESBL-producing Salmonella isolates were obtained from samples collected after 2005, and the percentage of resistant isolates increased significantly from 0% in 2004 to 27.9% in 2010 (P for trend = 0.006. This increase was caused in part by an increase in the number of Salmonella enterica subsp. enterica serovar Infantis strains harboring an approximately 280-kb plasmid containing bla(CMY-2 in proximity to ISEcp1. The dissemination of ESC-resistant Salmonella containing plasmid-mediated bla(CMY-2 in chicken

  1. Characterization of fluoroquinolone resistance and qnr diversity in Enterobacteriaceae from municipal biosolids.

    Directory of Open Access Journals (Sweden)

    Ella eKaplan

    2013-06-01

    Full Text Available Municipal biosolids produced during activated sludge treatment applied in waste water treatment plants, are significant reservoirs of antibiotic resistance, since they assemble both natural and fecal microbiota, as well as residual concentrations of antibiotic compounds. This raises major concerns regarding the environmental and epidemiological consequences of using them as fertilizers for crops. The second generation fluoroquinolone ciprofloxacin is probably the most abundant antibiotic compound detected in municipal biosolids due to its widespread use and sorption properties. Although fluoroquinolone resistance was originally thought to result from mutations in bacterial gyrase and topoisomerase IV genes, it is becoming apparent that it is also attributed to plasmid-associated resistance factors, which may propagate environmental antibiotic resistance. The objective of this study was to assess the impact of the activated sludge process on fluoroquinolone resistance. The scope of resistances and mobile genetic mechanisms associated with fluoroquinolone resistance were evaluated by screening large collections of ciprofloxacin-resistant Enterobacteriaceae strains from sludge (n=112 and from raw sewage (n=89. Plasmid-mediated quinolone resistance determinants (qnrA, B and S were readily detected in isolates from both environments, the most dominant being qnrS. Interestingly, all qnr variants were significantly more abundant in sludge isolates than in the isolates from raw sewage. Almost all of ciprofloxacin-resistant isolates were resistant to multiple antibiotic compounds. The sludge isolates were on the whole resistant to a broader range of antibiotic compounds than the raw sewage isolates; however this difference was not statistically significant. Collectively, this study indicates that the activated sludge selects for multiresistant bacterial strains, and that mobile quinolone-resistance elements may have a selective advantage in the activated

  2. Multidrug-resistant Gram-negative bacteria: a product of globalization.

    Science.gov (United States)

    Hawkey, P M

    2015-04-01

    Global trade and mobility of people has increased rapidly over the last 20 years. This has had profound consequences for the evolution and the movement of antibiotic resistance genes. There is increasing exposure of populations all around the world to resistant bacteria arising in the emerging economies. Arguably the most important development of the last two decades in the field of antibiotic resistance is the emergence and spread of extended-spectrum β-lactamases (ESBLs) of the CTX-M group. A consequence of the very high rates of ESBL production among Enterobacteriaceae in Asian countries is that there is a substantial use of carbapenem antibiotics, resulting in the emergence of plasmid-mediated resistance to carbapenems. This article reviews the emergence and spread of multidrug-resistant Gram-negative bacteria, focuses on three particular carbapenemases--imipenem carbapenemases, Klebsiella pneumoniae carbapenemase, and New Delhi metallo-β-lactamase--and highlights the importance of control of antibiotic use. Copyright © 2015. Published by Elsevier Ltd.

  3. Quinolone Resistance Reversion by Targeting the SOS Response.

    Science.gov (United States)

    Recacha, E; Machuca, J; Díaz de Alba, P; Ramos-Güelfo, M; Docobo-Pérez, F; Rodriguez-Beltrán, J; Blázquez, J; Pascual, A; Rodríguez-Martínez, J M

    2017-10-10

    question, we have generated E. coli mutants that exhibited a spectrum of SOS activity, ranging from a natural SOS response to a hypoinducible or constitutively suppressed response. We tested the effects of these mutations on quinolone resistance reversion under therapeutic concentrations in a set of isogenic strains carrying different combinations of chromosome- and plasmid-mediated quinolone resistance mechanisms with susceptible, low-level quinolone resistant, resistant, and highly resistant phenotypes. Our comprehensive analysis opens up a new strategy for reversing drug resistance by targeting the SOS response. Copyright © 2017 Recacha et al.

  4. Antimicrobial resistance determinants among anaerobic bacteria isolated from footrot.

    Science.gov (United States)

    Lorenzo, María; García, Nuria; Ayala, Juan Alfonso; Vadillo, Santiago; Píriz, Segundo; Quesada, Alberto

    2012-05-25

    Antibiotic resistance has been evaluated among 36 Gram negative and anaerobic bacilli (10 Bacteroides, 11 Prevotella, 7 Porphyromonas and 8 Fusobacterium strains) isolated from clinical cases of caprine and ovine footrot (necrotic pododermatitis). The initial analysis on this bacterial consortium evaluates the relationships existing among antimicrobial resistance determinants, phenotype expression and mobilization potential. The Bacteroides strains were generally resistant to penicillins, first-generation cephalosporins, tetracycline and erythromycin, and expressed low level of β-lactamase activity. The main determinants found among the Bacteroides strains were cepA and tetQ genes, conferring resistance to β-lactams and tetracycline, respectively. A general susceptibility to β-lactams was shown for most Prevotella, Porphyromonas and Fusobacterium strains, where none of the β-lactamase genes described in Bacteroides was detected. Resistance to tetracycline and/or erythromycin was found among the three bacterial groups. Although tetQ genes were detected for several Prevotella and Porphyromonas strains, a unique ermF positive was revealed among Prevotella strains. The expression of resistance markers was not related with the polymorphism of their coding sequences. However, the finding of sequence signatures for conjugative transposons in the vicinities of tetQ and ermF suggests a mobilization potential that might have contributed to the spread of antimicrobial resistance genes. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Conditional and inducible transgene expression in endothelial and hematopoietic cells using Cre/loxP and tetracycline-off systems.

    Science.gov (United States)

    Liu, Ju; Deutsch, Urban; Fung, Iris; Lobe, Corrinne G

    2014-11-01

    In the present study, the tetracycline-off and Cre/ loxP systems were combined to gain temporal and spatial control of transgene expression. Mice were generated that carried three transgenes: Tie2-tTA, tet-O-Cre and either the ZEG or ZAP reporter. Tie2-tTA directs expression of tetracycline-controlled transactivator (tTA) in endothelial and hematopoietic cells under the control of the Tie2 promoter. Tet-O-Cre produces Cre recombinase from a minimal promoter containing the tet-operator (tetO). ZEG or ZAP contains a strong promoter and a loxP -flanked stop sequence, followed by an enhanced green fluorescence protein (EGFP) or human placental alkaline phosphatase (hPLAP) reporter. In the presence of tetracycline, the tTA transactivator produced by Tie-2-tTA is disabled and Cre is not expressed. In the absence of tetracycline, the tTA binds tet-O-Cre to drive the expression of Cre, which recombines the loxP sites of the ZEG or ZAP transgene and results in reporter gene expression. In the present study, the expression of the ZEG or ZAP reporter genes in embryos and adult animals with and without tetracycline treatment was examined. In the presence of tetracycline, no reporter gene expression was observed. When tetracycline was withdrawn, Cre excision was activated and the reporter genes were detected in endothelial and hematopoietic cells. These results demonstrate that this system may be used to bypass embryonic lethality and access adult phenotypes.

  6. Evaluation of the MicroScan ESBL plus confirmation panel for detection of extended-spectrum beta-lactamases in clinical isolates of oxyimino-cephalosporin-resistant Gram-negative bacteria.

    Science.gov (United States)

    Stürenburg, Enno; Lang, Melanie; Horstkotte, Matthias A; Laufs, Rainer; Mack, Dietrich

    2004-11-01

    We aimed to assess the performance of the MicroScan ESBL plus confirmation panel using a series of 87 oxyimino-cephalosporin-resistant Gram-negative bacilli of various species. Organisms tested included 57 extended-spectrum beta-lactamase (ESBL) strains comprising Enterobacter aerogenes (3), Enterobacter cloacae (10), Escherichia coli (11), Klebsiella pneumoniae (26), Klebsiella oxytoca (3) and Proteus mirabilis (4). Also included were 30 strains resistant to oxyimino cephalosporins but lacking ESBLs, which were characterized with other resistance mechanisms, such as inherent clavulanate susceptibility in Acinetobacter spp. (4), hyperproduction of AmpC enzyme in Citrobacter freundii (2), E. aerogenes (3), E. cloacae (3), E. coli (4), Hafnia alvei (1) and Morganella morganii (1), production of plasmid-mediated AmpC beta-lactamase in K. pneumoniae (3) and E. coli (3) or hyperproduction of K1 enzyme in K. oxytoca (6). The MicroScan MIC-based clavulanate synergy correctly classified 50 of 57 ESBL strains as ESBL-positive and 23 of 30 non-ESBL strains as ESBL-negative (yielding a sensitivity of 88% and a specificity of 76.7%, respectively). False negatives among ESBL producers were highest with Enterobacter spp. due to masking interactions between ESBL and AmpC beta-lactamases. False-positive classifications occurred in two Acinetobacter spp., one E. coli producing plasmid-mediated AmpC beta-lactamase and two K. oxytoca hyperproducing their chromosomal K1 beta-lactamase. The MicroScan clavulanate synergy test proved to be a valuable tool for ESBL confirmation. However, this test has limitations in detecting ESBLs in Enterobacter spp. and in discriminating ESBL-related resistance from the K1 enzyme and from inherent clavulanate susceptibility in Acinetobacter spp.

  7. Total resistance of native bacteria as an indicator of changes in the water environment

    Energy Technology Data Exchange (ETDEWEB)

    Harnisz, Monika [Department of Environmental Microbiology, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1, 10-957 Olsztyn (Poland)

    2013-03-15

    This study analyzes changes in the total (intrinsic and acquired) resistance of autochthonous bacteria in a river which is a receiver of treated wastewater. In the analyzed samples, tetracycline contamination levels were low and characteristic of surface water bodies. An increase in the populations of tetracycline-resistant and fluoroquinolone-resistant microorganisms was noted in downstream river water samples in comparison with upstream river water samples, but the above trend was not observed in bacteria resistant to macrolides and β-lactams. The counts of doxycycline-resistant bacteria (DOX{sup R}) were significantly correlated with doxycycline levels. The minimum inhibitory concentrations (MICs) for doxycycline in DOX{sup R} isolates were higher in downstream river water than in upstream river water samples. The discharge of treated wastewater had no effect on the multi-drug resistance of oxytetracycline-resistant and doxycycline-resistant isolates. The results of the experiment indicate that the presence of doxycycline-resistant bacteria is a robust indicator of anthropogenic stress in river water. -- Highlights: ► The total resistance of native bacteria in river which is a receiver of treated wastewater was analyzed. ► Tetracyclines contamination levels were low. ► The counts of doxycycline-resistant bacteria were correlated with doxycycline levels. -- The presence of doxycycline-resistant bacteria in rivers can be a robust indicator of anthropogenic stress.

  8. Total resistance of native bacteria as an indicator of changes in the water environment

    International Nuclear Information System (INIS)

    Harnisz, Monika

    2013-01-01

    This study analyzes changes in the total (intrinsic and acquired) resistance of autochthonous bacteria in a river which is a receiver of treated wastewater. In the analyzed samples, tetracycline contamination levels were low and characteristic of surface water bodies. An increase in the populations of tetracycline-resistant and fluoroquinolone-resistant microorganisms was noted in downstream river water samples in comparison with upstream river water samples, but the above trend was not observed in bacteria resistant to macrolides and β-lactams. The counts of doxycycline-resistant bacteria (DOX R ) were significantly correlated with doxycycline levels. The minimum inhibitory concentrations (MICs) for doxycycline in DOX R isolates were higher in downstream river water than in upstream river water samples. The discharge of treated wastewater had no effect on the multi-drug resistance of oxytetracycline-resistant and doxycycline-resistant isolates. The results of the experiment indicate that the presence of doxycycline-resistant bacteria is a robust indicator of anthropogenic stress in river water. -- Highlights: ► The total resistance of native bacteria in river which is a receiver of treated wastewater was analyzed. ► Tetracyclines contamination levels were low. ► The counts of doxycycline-resistant bacteria were correlated with doxycycline levels. -- The presence of doxycycline-resistant bacteria in rivers can be a robust indicator of anthropogenic stress

  9. Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil.

    Science.gov (United States)

    Pereira, M S; Siqueira-Júnior, J P

    1995-06-01

    Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.

  10. In Vivo Transmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness.

    Science.gov (United States)

    Johnson, Timothy J; Singer, Randall S; Isaacson, Richard E; Danzeisen, Jessica L; Lang, Kevin; Kobluk, Kristi; Rivet, Bernadette; Borewicz, Klaudyna; Frye, Jonathan G; Englen, Mark; Anderson, Janet; Davies, Peter R

    2015-05-15

    IncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensal Escherichia coli host. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containing E. coli from pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containing E. coli in pig feces (P IncA/C plasmid to other indigenous E. coli hosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other than E. coli. In vitro competition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage in E. coli and Salmonella. In vitro transfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracycline in vitro strongly selected for IncA/C plasmid-containing E. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  11. Aspiration and tetracycline sclerotherapy of primary vaginal hydrocoele of testis in adults

    International Nuclear Information System (INIS)

    Ali, J.; Anwar, W.

    2008-01-01

    Primary Vaginal Hydrocoele of Testis is a common condition which is primarily treated surgically. Many patients with Hydrocoele of testis are either not willing or are unfit for surgery. This study was done to know the safety, efficacy and out come of tetracycline induced sclerotherapy of Primary Vaginal Hydrocoele of Testis in adults. This quasi experimental study was done in Shahina Jamil Hospital, attached with Frontier Medical College and Ayub Teaching Hospital, Abbottabad from March 2006 to April, 2007. Thirty-seven patients with primary vaginal hydrocoele were included in the study. Aspiration and instillation of Tetracycline was done after spermatic cord block with 2% lignocaine. Procedure time, Peri and Post-procedure complications, number of injections for cure and patients satisfaction with the procedure were recorded. Patients were discharged home 3 to 4 hours after the procedure and followed up after one week, one month, three months and six months. Direct admission and re-admissions were recorded. The mean age of patients was 47 years. Mean procedure time was 45 minutes. All patients were cured. Mild postoprocedure pain occurred in 12 (40%), moderate pain in 14 (46%) patients and severe pain in 4 (13.3%) patients. No patient developed haematoma or local infection. One patient (3.3%) had micturition problem. Two (6.6%) patients had minimal recurrence. One injection was sufficient for cure in all patients, 28 (93%) patients were satisfied while 2 (6.6%) patients were not satisfied with this procedure. No patient was admitted in the hospital after the procedure. Aspiration and injection of tetracycline in Primary vaginal Hydrocoele of Testis in adults is safe, effective and very economical procedure. (author)

  12. Aspiration and tetracycline sclerotherapy of primary vaginal hydrocoele of testis in adults.

    Science.gov (United States)

    Ali, Johar; Anwar, Waqas; Akbar, Mohammad; Akbar, Syed Ali; Zafar, Arshad

    2008-01-01

    Primary Vaginal Hydrocoele of Testis is a common condition which is primarily treated surgically. Many patients with Hydrocoele of testis are either not willing or are unfit for surgery. This study was done to know the safety, efficacy and out come of tetracycline induced sclerotherapy of Primary Vaginal Hydrocoele of Testis in adults. This quasi experimental study was done in Shahina Jamil Hospital, attached with Frontier Medical College and Ayub Teaching Hospital, Abbottabad from March 2006 to April, 2007. Thirty-seven patients with primary vaginal hydrocoele were included in the study. Aspiration and instillation of Tetracycline was done after spermatic cord block with 2% lignocaine. Procedure time, Peri and Post-procedure complications, number of injections for cure and patients' satisfaction with the procedure were recorded. Patients were discharged home 3 to 4 hours after the procedure and followed up after one week, one month, three months and six months. Direct admission and re-admissions were recorded. The mean age of patients was 47 years. Mean procedure time was 45 minutes. All patients were cured. Mild postoprocedure pain occurred in 12 (40%), moderate pain in 14 (46%) patients and severe pain in 4 (13.3%) patients. No patient developed haematoma or local infection. One patient (3.3%) had micturition problem. Two (6.6%) patients had minimal recurrence. One injection was sufficient for cure in all patients. 28 (93%) patients were satisfied while 2 (6.6%) patients were not satisfied with this procedure. No patient was admitted in the hospital after the procedure. Aspiration and injection of tetracycline in Primary vaginal Hydrocoele of Testis in adults is safe, effective and very economical procedure.

  13. Emerging antimicrobial resistance pattern of Helicobacter pylori in central Gujarat

    Directory of Open Access Journals (Sweden)

    H B Pandya

    2014-01-01

    Full Text Available Background: Antimicrobial resistance is a growing problem in H. pylori treatment. The study was intended to evaluate the prevalence of resistance amongst 80 H.pylori isolates cultured from biopsy taken during routine endoscopies in 2008-2011. Materials and Methods: 855 gastro duodenal biopsies were collected and cultured on H.pylori selective medium (containing Brucella agar and Columbia agar (Hi media, with Skirrow′s supplement (antibiotic supplement and 7% human blood cells. H.pylori was isolated from 80 specimens. The antimicrobial susceptibility of H.pylori isolates was carried out by the Kirby Bauer technique against metronidazole (5 µg, clarithromycin (15 µg, ciprofloxacin (5 µg, amoxicillin (10 µg, tetracycline (30 µg, erythromycin (15 µg, levofloxacin (5 µg, and furazolidone (50 µg (Sigma- Aldrich, MO. Results: 83.8% isolates were resistant to metronidazole, 58.8% were resistant to Clarithromycin 72.5% were resistant to Amoxicillin, 50% to Ciprofloxacin and 53.8% to tetracycline. furazolidone, erythromycin and Levofloxacin showed only 13.8% resistance to H.pylori. Multi drug resistance with metronidazole+ clarithromycin+ tetracycline was 85%. For all the drugs Antimicrobial resistance rate was found higher in males compare to females. Metronidazole and amoxicillin resistance was found noteworthy in patients with duodenal ulcer (p = 0.018, gastritis (P = 0.00, and in reflux esophagitis (P = 0.00. clarithromycin and tetracycline resistance was suggestively linked with duodenitis (P = 0.018, while furazolidone, erythromycin and levofloxacin showed excellent sensitivity in patients with duodenitis (P value- 0.018, gastritis (P= 0.00 and reflux esophagitis (P = 0.00. Resistance with metronidazole (P = 0.481, clarithromycin (P= 0.261, amoxicillin (P = 0.276, tetracycline (P = 0.356, ciprofloxacin (P = 0.164 was not correlated well with Age-group and Gender of the patients. Conclusion: A very high percentage of patients were infected

  14. Influence of local tetracycline on the microbiota of alveolar osteitis in rats

    OpenAIRE

    Bosco, Joseane Maria Dias; Oliveira, Sérgio Ricardo de; Bosco, Álvaro Francisco; Schweitzer, Christiane Marie; Jardim Júnior, Elerson Gaetti

    2008-01-01

    The aim of the present study was to evaluate the effects of local tetracycline on the occurrence of alveolar osteitis in rats, and on the microbiota associated to this infection. Forty Wistar rats were randomly assigned to 4 groups (n=10): I - the rats had the maxillary right incisor extracted and the alveolar wound did not receive any treatment; II - adrenaline and Ringer-PRAS were introduced into the alveolar wound; III - the alveolar wound was irrigated with sterile saline; and IV - the al...

  15. Preparation and control of ) 7sup(99m)Tc-Sn{tetracycline antibiotics. )

    International Nuclear Information System (INIS)

    Machan, V.; Kalincak, M.; Barna, K.

    1976-01-01

    A simple method for the preparation of ) 7sup(99m)Tc-Sn{-tetracycline, 7sup(99m)Tc-Sn{-oxytetracycline and 7sup(99m)Tc-Sn{-rolitetracycline for routine applications in nuclear medicine is described. Attention is paid to the quality control of these preparations. Paper chromatography in absolute acetone and 85% methanol is compared with gel chromatography on Sephadex G-10. The radiochemical stability of the preparations was observed for a period of up to 24 hours after preparation under various storage conditions. (author). )

  16. Adverse effect of tetracycline and doxycycline on reproductive tract development of CD1 mice

    Czech Academy of Sciences Publication Activity Database

    Elzeinová, Fatima; Pěknicová, Jana; Děd, Lukáš; Dorosh, Andriy; Kubátová, Alena; Margaryan, Hasmik; Makovický, P.; Rajmon, R.

    2012-01-01

    Roč. 67, Issue Supplement s1 (2012), s. 47-48 ISSN 1046-7408. [13th International Symposium for Immunology of reproduction "From the roots to the tops of Reproductive Immunology". 22.06.2012-24.06.2012, Varna] R&D Projects: GA ČR(CZ) GA523/09/1793; GA ČR(CZ) GAP503/12/1834 Institutional research plan: CEZ:AV0Z50520701 Keywords : tetracycline * doxycycline * CD1 mice * reproduction Subject RIV: DN - Health Impact of the Environment Quality

  17. PCR detection of oxytetracycline resistance genes from diverse habitats in total community DNA and in streptomycete isolates.

    NARCIS (Netherlands)

    Nikolakopoulou, T.L.; Egan, S.; Overbeek, van L.S.; Guillaume, G.; Heuer, H.; Wellington, E.M.H.; Elsas, van J.D.; Collard, J.M.; Smalla, K.; Karagouni, A.D.

    2005-01-01

    A range of European habitats was screened by PCR for detection of the oxytetracycline resistance genes otr(A) and otr(B), found in the oxytetracycline-producing strain Streptomyces rimosus. Primers were developed to detect these otr genes in tetracycline-resistant (TcR) streptomycete isolates from

  18. Antimicrobial resistance in Escherichia coli and Salmonella spp. isolates from fresh produce and the impact to food safety.

    Science.gov (United States)

    Vital, Pierangeli G; Caballes, Marie Bernadine D; Rivera, Windell L

    2017-09-02

    Foodborne diseases associated with fresh produce consumption have escalated worldwide, causing microbial safety of produce of critical importance. Bacteria that have increasingly been detected in fresh produce are Escherichia coli and Salmonella spp., both of which have been shown to progressively display antimicrobial resistance. The study focused on the assessment of antimicrobial resistance of these enteric bacteria from different kinds of fresh produce from various open air markets and supermarkets in the Philippines. Using the disk diffusion assay on a total of 50 bacterial isolates obtained from 410 fresh produce surveyed, monoresistance to tetracycline was observed to be the most prevalent (38%), followed by multidrug resistance to tetracycline, chloramphenicol, ciprofloxacin, and nalidixic acid (4%), and lastly by dual resistance to tetracycline and chloramphenicol (2%). Using multiplex and simplex polymerase chain reaction (PCR) assays, tetA (75%) and tetB (9%) were found in tetracycline resistant isolates, whereas catI (67%) and catIII (33%) were detected in chloramphenicol resistant isolates. Sequence analysis of gyr and par genes from the ciprofloxacin and nalidixic acid resistant isolates revealed different mutations. Based on the results, fresh produce act as a reservoir of these antibiotic resistant bacteria which may pose health threat to consumers.

  19. Antimicrobial resistance in Enterobacteriaceae in Brazil: focus on β-lactams and polymyxins.

    Science.gov (United States)

    Sampaio, Jorge Luiz Mello; Gales, Ana Cristina

    2016-12-01

    During the last 30 years there has been a dissemination of plasmid-mediated β-lactamases in Enterobacteriaceae in Brazil. Extended spectrum β-lactamases (ESBL) are widely disseminated in the hospital setting and are detected in a lower frequency in the community setting. Cefotaximases are the most frequently detected ESBL type and Klebsiella pneumoniae is the predominant species among ESBL producers. Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae became widely disseminated in Brazil during the last decade and KPC production is currently the most frequent resistance mechanism (96.2%) in carbapenem resistant K. pneumoniae. To date KPC-2 is the only variant reported in Brazil. Polymyxin B resistance in KPC-2-producing K. pneumoniae has come to an alarming rate of 27.1% in 2015 in São Paulo, the largest city in Brazil. New Delhi metallo-β-lactamase was detected in Brazil in 2013, has been reported in different Brazilian states but are not widely disseminated. Antimicrobial resistance in Enterobacteriaceae in Brazil is a very serious problem that needs urgent actions which includes both more strict adherence to infection control measures and more judicious use of antimicrobials. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  20. Occurrence of integrons and resistance genes among sulphonamide-resistant Shigella spp. from Brazil

    DEFF Research Database (Denmark)

    Peirano, G.; Agersø, Yvonne; Aarestrup, Frank Møller

    2005-01-01

    Objectives: To determine the occurrence of class 1 and 2 integrons and antimicrobial resistance genes among sulphonamide-resistant Shigella strains isolated in Brazil during 1999-2003. Methods: Sixty-two Shigella (Shigella flexneri, n = 47 and Shigella sonnei, n = 15) were tested against 21...... antimicrobial agents. The presence of integrons classes 1 and 2 and antimicrobial resistance genes was investigated by PCR using specific primers. Results: A total of eight antimicrobial resistance profiles were identified, with the profile of resistance to sulfamethoxazole, trimethoprim, spectinomycin...... of 2214 bp harbouring a gene cassette array conferring resistance to trimethoprim, streptothricin and spectinomycin/streptomycin. The genes coding for resistance to chloramphenicol (catA1), tetracycline [tet(A) and tet(B)] and ampicillin (bla(OXA) and bla(TEM)), were detected in resistant strains...

  1. Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs.

    Science.gov (United States)

    Harada, Kazuki; Niina, Ayaka; Shimizu, Takae; Mukai, Yujiro; Kuwajima, Ken; Miyamoto, Tadashi; Kataoka, Yasushi

    2014-11-01

    Large-scale monitoring of resistance to 14 antimicrobial agents was performed using 103 Proteus mirabilis strains isolated from dogs in Japan. Resistant strains were analysed to identify their resistance mechanisms. Rates of resistance to chloramphenicol, streptomycin, enrofloxacin, trimethoprim/sulfamethoxazole, kanamycin, ampicillin, ciprofloxacin, cephalothin, gentamicin, cefoxitin and cefotaxime were 20.4, 15.5, 12.6, 10.7, 9.7, 8.7, 5.8, 2.9, 2.9, 1.9 and 1.9%, respectively. No resistance to ceftazidime, aztreonam or imipenem was found. Class 1 and 2 integrases were detected in 2.9 and 11.7% of isolates, respectively. Class 1 integrons contained aadB or aadB-catB-like-blaOXA10-aadA1, whereas those of class 2 contained sat-aadA1, dhfr1-sat-aadA1 or none of the anticipated resistance genes. Of five distinct plasmid-mediated quinolone-resistance (PMQR) genes, only qnrD gene was detected in 1.9% of isolates. Quinolone-resistance determining regions (QRDRs) of gyrA and parC from 13 enrofloxacin-intermediate and -resistant isolates were sequenced. Seven strains had double mutations and three had single mutations. Three of nine ampicillin-resistant isolates harboured AmpC-type β-lactamases (i.e. blaCMY-2, blaCMY-4 and blaDHA-1). These results suggest that canine Proteus mirabilis deserves continued surveillance as an important reservoir of antimicrobial resistance determinants. This is the first report, to our knowledge, describing integrons, PMQRs and QRDR mutations in Proteus mirabilis isolates from companion animals. © 2014 The Authors.

  2. Evaluation of the HB&L carbapenemase and extended spectrum beta lactamase-AmpC automated screening kits for the rapid detection of resistant Enterobacteriaceae in rectal swabs

    Directory of Open Access Journals (Sweden)

    Sara Marani

    2017-03-01

    Full Text Available Background. In the past two decades, a rapid increase of infections due to multidrug-resistant Enterobacteriaceae was reported worldwide, including in Italy. These bacteria express genes encoding for extended-spectrum β-lactamases (ESBL or bear a plasmid-mediated AmpC that induce phenotypically a resistance to the last-generation cephalosporins; even more worrying is the rapid increase of Enterobacteriaceae carrying genes conferring resistance to carbapenems (CPE. Materials and methods. The gut may serve as reservoir for these antibiotic drug-resistant bacteria: as a consequence, the rapid detection of drug resistant Enterobacteriaceae from rectal swabs is an important tool to identify rectal carriage of resistant bacteria. This procedure is the basic tool to successfully implement the infection control measures in the hospital wards. The study evaluated the capability of the HB&L ESBL/AmpC and CARBAPENEMASE screening kit (Alifax, Padua, Italy to rapidly identify the drug resistant enterobacteriaceae from rectal swabs: the performance was compared with the conventional method. Results and conclusions. The overall agreement was very good (91% for the detection of ESBL-AmpC, and 96.2% for the identification of CPE; this method is thus an efficient tool to quickly report positive multidrug resistant bacteria in rectal swabs.

  3. Molecular screening of antibiotic-resistant determinants among multidrug-resistant clinical isolates of Proteus mirabilis from SouthWest Nigeria.

    Science.gov (United States)

    Alabi, Olumuyiwa Samuel; Mendonça, Nuno; Adeleke, Olufemi Ezekiel; da Silva, Gabriela Jorge

    2017-06-01

    Globally, and particularly in developing countries, the menace of anti-microbial resistance is an accelerating problem. In Nigeria, increase in bacterial resistance has been phenotypically established but due to high cost, few molecular studies have been reported. This study screened for presence of transferable resistance genes and mobile genetic elements (MGEs) such as integron among multi-drug resistant (MDR) P. mirabilis . A total of 108 P. mirabilis strains collected from five tertiary hospitals in SouthWest Nigeria were subjected to antibiotic susceptibility study using disc-diffusion method. Transferable resistance genes and MGEs were amplified using Polymerase chain reaction (PCR) analysis and amplicons sequenced. Varied resistance was observed against all the antibiotics tested. About 56% of the isolates were MDR including those from 0-12 years old children. PCR analysis revealed the presence of aac(6')-Ib (33.3%), plasmid mediated quinolone resistance (PMQR) genes [qnrA (36.7%), acc(6')-Ib-cr (5%)], TEM (48.3%), CTX-M (6.7%) and integrons class 1 (58.3%) and class 2 (26.7%). Sequencing analysis revealed bla TEM-1 , bla CTX-M-15 associated with IS Ecp1 and eight different arrays of gene cassettes: aadA1, aadA1-qacH, aadB-aadA2, aadA5, dfrA7, dfrA15, dfrA17, dfrA17-aadA5 . Transferable resistance genes in association with MGEs are present in Nigerian P. mirabilis thus their potential in disseminating resistance.

  4. Occurrence of antibiotic resistance and characterization of resistant genes and integrons in Enterobacteriaceae isolated from integrated fish farms south China

    Science.gov (United States)

    Su, Hao-Chang; Ying, Guang-Guo; Tao, Ran; Zhang, Rui-Quan; Fogarty, Lisa R.; Kolpin, Dana W.

    2011-01-01

    Antibiotics are still widely applied in animal husbandry to prevent diseases and used as feed additives to promote animal growth. This could result in antibiotic resistance to bacteria and antibiotic residues in animals. In this paper, Enterobacteriaceae isolated from four integrated fish farms in Zhongshan, South China were tested for antibiotic resistance, tetracycline resistance genes, sulfonamide resistance genes, and class 1 integrons. The Kirby-Bauer disk diffusion method and polymerase chain reaction (PCR) assays were carried out to test antibiotic susceptibility and resistance genes, respectively. Relatively high antibiotic resistance frequencies were found, especially for ampicillin (80%), tetracycline (52%), and trimethoprim (50%). Out of 203 Enterobacteriaceae isolates, 98.5% were resistant to one or more antibiotics tested. Multiple antibiotic resistance (MAR) was found highest in animal manures with a MAR index of 0.56. Tetracycline resistance genes (tet(A), tet(C)) and sulfonamide resistance genes (sul2) were detected in more than 50% of the isolates. The intI1 gene was found in 170 isolates (83.7%). Both classic and non-classic class 1 integrons were found. Four genes, aadA5, aadA22, dfr2, and dfrA17, were detected. To our knowledge, this is the first report for molecular characterization of antibiotic resistance genes in Enterobacteriaceae isolated from integrated fish farms in China and the first time that gene cassette array dfrA17-aadA5 has been detected in such fish farms. Results of this study indicated that fish farms may be a reservoir of highly diverse and abundant antibiotic resistant genes and gene cassettes. Integrons may play a key role in multiple antibiotic resistances posing potential health risks to the general public and aquaculture.

  5. Evaluation of commercially available biodegradable tetracycline fiber therapy in chronic periodontitis

    Science.gov (United States)

    Sachdeva, Surinder; Agarwal, Vipin

    2011-01-01

    Background: Chronic periodontitis is an inflammatory disorder caused by dental plaque having mixed microbial flora. The different treatment modalities available to treat this disease are aimed at removal of micro-organisms from both hard and soft tissues. Systemic as well as local anti-microbial agents are helpful adjuncts in reducing microbes especially in inaccessible areas along with mechanical debridement therapy. Materials and Methods: The study was conducted in a split mouth design. Thirty-five patients having at least two non-adjacent sites in different quadrants with periodontal pockets ≥5 mm and with bleeding on probing at initial visit were selected. The selected sites were treated with both scaling and root planing plus tetracycline fibers or with scaling and root planing alone. Baseline and follow-up measurements included plaque index, gingival index, probing pocket depth, and clinical attachment level. Result: Both treatment modalities were affective in improving clinical parameters over three months’ observation period. The combined antimicrobial and mechanical debridement therapy has shown better results as compared with scaling and root planing alone. Conclusion: Application of tetracycline in modified collagen matrix following scaling and root planing might be beneficial in treatment of chronic periodontitis and improving periodontal parameters for 3-month duration. PMID:21976836

  6. Removal of tetracyclines, sulfonamides, and quinolones by industrial-scale composting and anaerobic digestion processes.

    Science.gov (United States)

    Liu, Hang; Pu, Chengjun; Yu, Xiaolu; Sun, Ying; Chen, Junhao

    2018-02-15

    This study evaluated and compared the removal of antibiotics by industrial-scale composting and anaerobic digestion at different seasons. Twenty compounds belonged to three classes of widely used veterinary antibiotics (i.e., tetracyclines, sulfonamides, and quinolones) were investigated. Results show that of the three groups of antibiotics, tetracyclines were dominant in swine feces and poorly removed by anaerobic digestion with significant accumulation in biosolids, particularly in winter. Compared to that in winter, a much more effective removal (> 97%) by anaerobic digestion was observed for sulfonamides in summer. By contrast, quinolones were the least abundant antibiotics in swine feces and exhibited a higher removal by anaerobic digestion in winter than in summer. The overall removal of antibiotics by aerobic composting could be more than 90% in either winter or summer. Nevertheless, compost products from livestock farms in Beijing contained much higher antibiotics than commercial organic fertilizers. Thus, industrial composting standards should be strictly applied to livestock farms to further remove antibiotics and produce high quality organic fertilizer.

  7. Controlled release of tetracycline-HCl from halloysite-polymer composite films.

    Science.gov (United States)

    Ward, Christopher J; Song, Shang; Davis, Edward W

    2010-10-01

    The first direct comparison between two common methods for loading halloysite with a small molecule for controlled release is presented. While the methods differ in the degree of simplicity, they provide essentially the same level of loading and release kinetics. A tentative explanation of the "burst" effect often seen in the release of low molecular weight molecules from halloysite is provided. The ability of halloysite to mediate the release rate of a water soluble drug, tetracycline, from solution cast polyvinyl alcohol and polymethyl methacrylate films was evaluated. In some films, montmorillonite was also incorporated. The addition of montmorillonite to solutions used to cast tetracycline containing films significantly reduced the release rate from the dried films. The same overall effect was seen when the drug was loaded into halloysite prior to preparation of the films. In both cases, the release was best fit with the simple Higuchi model. However, when montmorillonite was added to solutions of polyvinyl alcohol and drug loaded halloysite the release profiles were better fit by the Ritgar-Peppas model for anomalous transport. Release from polymethyl methacrylate was reduced by a factor of three by incorporating the drug in halloysite prior to producing the films.

  8. Feasibility of a tetracycline-binding method for detecting synovial fluid basic calcium phosphate crystals.

    Science.gov (United States)

    Rosenthal, Ann K; Fahey, Mark; Gohr, Claudia; Burner, Todd; Konon, Irina; Daft, Laureen; Mattson, Eric; Hirschmugl, Carol; Ryan, Lawrence M; Simkin, Peter

    2008-10-01

    Basic calcium phosphate (BCP) crystals are common components of osteoarthritis (OA) synovial fluid. Progress in understanding the role of these bioactive particles in clinical OA has been hampered by difficulties in their identification. Tetracyclines stain calcium phosphate mineral in bone. The aim of this study was to investigate whether tetracycline staining might be an additional or alternative method for identifying BCP crystals in synovial fluid. A drop of oxytetracycline was mixed with a drop of fluid containing synthetic or native BCP, calcium pyrophosphate dihydrate (CPPD), or monosodium urate (MSU) crystals and placed on a microscope slide. Stained and unstained crystals were examined by light microscopy, with and without a portable broad-spectrum ultraviolet (UV) pen light. A small set of characterized synovial fluid samples were compared by staining with alizarin red S and oxytetracycline. Synthetic BCP crystals in synovial fluid were quantified fluorimetrically using oxytetracycline. After oxytetracycline staining, synthetic and native BCP crystals appeared as fluorescent amorphous aggregates under UV light. Oxytetracycline did not stain CPPD or MSU crystals or other particulates. Oxytetracycline staining had fewer false-positive test results than did alizarin red S staining and could provide estimates of the quantities of synthetic BCP crystals in synovial fluid. With further validation, oxytetracycline staining may prove to be a useful adjunct or alternative to currently available methods for identifying BCP crystals in synovial fluid.

  9. Sensitivity and Selectivity on Aptamer-Based Assay: The Determination of Tetracycline Residue in Bovine Milk

    Directory of Open Access Journals (Sweden)

    Sohee Jeong

    2012-01-01

    Full Text Available A competitive enzyme-linked aptamer assay (ELAA to detect tetracycline in milk was performed by using two different aptamers individually; one is 76 mer-DNA aptamer and the other is 57 mer-RNA aptamer. The best optimum condition was obtained without monovalent ion, Na+ and also by adding no Mg2+ ion in the assay buffer, along with RT incubation. The optimized ELAA showed a good sensitivity (LOD of 2.10 × 10−8 M with a wide dynamic range (3.16 × 10−8 M ~ 3.16 × 10−4 M. In addition, the average R.S.D. across all data points of the curve was less than 2.5% with good recoveries (~101.8% from the milk media. Thus, this method provides a good tool to monitor tetracycline in milk from MRLs’ point of view. However, this ELAA method was not superior to the ELISA method in terms of specificity. This paper describes that it does not always give better sensitivity and specificity in assays even though aptamers have several advantages over antibodies and have been known to be good binders for binding assays.

  10. Non-antibacterial tetracycline formulations: clinical applications in dentistry and medicine

    Directory of Open Access Journals (Sweden)

    Ying Gu

    2012-10-01

    Full Text Available In 1983, it was first reported that tetracyclines (TCs can modulate the host response, including (but not limited to inhibition of pathologic matrix metalloproteinase (MMP activity, and by mechanisms unrelated to the antibacterial properties of these drugs. Soon thereafter, strategies were developed to generate non-antibacterial formulations (subantimicrobial-dose doxycycline; SDD and compositions (chemically modified tetracyclines; CMTs of TCs as host-modulating drugs to treat periodontal and other inflammatory diseases. This review focuses on the history and rationale for the development of: (a SDD which led to two government-approved medications, one for periodontitis and the other for acne/rosacea and (b CMTs, which led to the identification of the active site of the drugs responsible for MMP inhibition and to studies demonstrating evidence of efficacy of the most potent of these, CMT-3, as an anti-angiogenesis agent in patients with the cancer, Kaposi's sarcoma, and as a potential treatment for a fatal lung disease (acute respiratory distress syndrome; ARDS. In addition, this review discusses a number of clinical studies, some up to 2 years’ duration, demonstrating evidence of safety and efficacy of SDD formulations in humans with oral inflammatory diseases (periodontitis, pemphigoid as well as medical diseases, including rheumatoid arthritis, post-menopausal osteopenia, type II diabetes, cardiovascular diseases, and a rare and fatal lung disease, lymphangioleiomyomatosis.

  11. Tetracycline removal from water by adsorption/bioadsorption on activated carbons and sludge-derived adsorbents.

    Science.gov (United States)

    Rivera-Utrilla, José; Gómez-Pacheco, Carla V; Sánchez-Polo, Manuel; López-Peñalver, Jesús J; Ocampo-Pérez, Raúl

    2013-12-15

    The objective of this study was to analyze the behavior of activated carbons with different chemical and textural natures in the adsorption of three tetracyclines (TCs) (tetracycline, oxytetracycline, and chlortetracycline). We also assessed the influence of the solution pH and ionic strength on the adsorption of these compounds and studied their removal by the combined use of microorganisms and activated carbon (bioadsorption). Sludge-derived materials were also used to remove TC from water. The capacity of these materials to adsorb TC was very high and was much greater than that of commercial activated carbon. This elevated adsorption capacity (512.1-672.0 mg/g) is explained by the high tendency of TC to form complex ions with some of the metal ions present in these materials. The medium pH and presence of electrolytes considerably affected TCs adsorption on commercial activated carbon. These results indicate that electrostatic adsorbent-adsorbate interactions play an important role in TC adsorption processes when conducted at pH values that produce TC deprotonation. The presence of bacteria during the TCs adsorption process decreases their adsorption/bioadsorption on the commercial activated carbon, weakening interactions between the adsorbate and the microfilm formed on the carbon surface. The adsorptive capacity was considerably lower in dynamic versus static regime, attributable to problems of TC diffusion into carbon pores and the shorter contact time between adsorbate and adsorbent. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Spectrophotometric Determination of Terbutaline Sulphate and Tetracycline Hydrochloride via ion pair Complex Formation Using Eosin Y

    Directory of Open Access Journals (Sweden)

    Mohamed Y. Dhamra

    2014-06-01

    Full Text Available A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of terbutaline sulphate and tetracycline hydrochloride drugs in pure form and pharmaceutical formulations. The proposed method is based on the formation of binary complexes between these drugs and eosin Y in aqueous acetate buffered medium. Under the optimum conditions, the binary complexes showed absorption maxima at 545 nm. Beer's law was rectilinear over concentration range of 0.5-10 and 5-45 μg/mL, R2 were 0.9984 and 0.9988, RSD were ≤ 0.72 and ≤ 0.19 (n=5 with average recovery % 101.42 % and 100.08 % and the average recovery values of pharmaceutical formulations 101.48 and 98.01 for above drugs respectively. The limit of detection (LOD were 0.030 and 0.613 μg/mL and limit of quantitation (LOQ were 0.103 and 2.00 μg/mL with molar absorptivity values 3.169  103 and 6.347  103 l. mol-1. cm-1 and the relative standard deviation values ≤0.720 and ≤ 0.19 for both drugs respectively. No interference was observed from the excipients that are commonly present in pharmaceutical formulations. The proposed method was successfully applied to the analysis of terbutaline sulphate tablet and tetracycline hydrochloride capsule in their dosage forms.

  13. Spectrophotometric determination of terbutaline sulphate and tetracycline hydrochloride via ion pair complex formation using eosin y

    International Nuclear Information System (INIS)

    Dhamra, M.Y.; Sabha, T.N.A.; Ghabsha, T.S.A.

    2014-01-01

    A simple, sensitive and rapid spectrophotometric method was developed and validated for the determination of terbutaline sulphate and tetracycline hydrochloride drugs in pure form and pharmaceutical formulations. The proposed method is based on the formation of binary complexes between these drugs and eosin Y in aqueous acetate buffered medium. Under the optimum conditions, the binary complexes showed absorption maxima at 545 nm. Beer's law was rectilinear over concentration range of 0.5-10 and 5-45 micro g/mL, R/sub 2/ were 0.9984 and 0.9988, RSD were 0.72 and 0.19 (n=5) with average recovery 101.42 % and 100.08 % and the average recovery values of pharmaceutical formulations 101.48 and 98.01 for above drugs respectively. The limit of detection (LOD) were 0.030 and 0.613 micro g/mL and limit of quantitation (LOQ) were 0.103 and 2.00 micro g/mL with molar absorptivity values 3.169 10/sup 3/ and 6.347 10/sup 3/l. mol/sup -1/. Cm/sup -1/ and the relative standard deviation values 0.720 and 0.19 for both drugs respectively. No interference was observed from the excipients that are commonly present in pharmaceutical formulations. The proposed method was successfully applied to the analysis of terbutaline sulphate tablet and tetracycline hydrochloride capsule in their dosage forms. (author)

  14. Effect of citric acid, tetracycline, and doxycycline on instrumented periodontally involved root surfaces: A SEM study

    Directory of Open Access Journals (Sweden)

    Gurparkash Singh Chahal

    2014-01-01

    Full Text Available Background: A surface smear layer consisting of organic and inorganic material is formed on the root surface following mechanical instrumentation and may inhibit the formation of new connective tissue attachment to the root surface. Modification of the tooth surface by root conditioning has resulted in improved connective tissue attachment and has advanced the goal of reconstructive periodontal treatment. Aim: The aim of this study was to compare the effects of citric acid, tetracycline, and doxycycline on the instrumented periodontally involved root surfaces in vitro using a scanning electron microscope. Settings and Design: A total of 45 dentin samples obtained from 15 extracted, scaled, and root planed teeth were divided into three groups. Materials and Methods: The root conditioning agents were applied with cotton pellets using the "Passive burnishing technique" for 5 minutes. The samples were then examined by the scanning electron microscope. Statistical Analysis Used: The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, version 15.0 for Windows. For all quantitative variables means and standard deviations were calculated and compared. For more than two groups ANOVA was applied. For multiple comparisons post hoc tests with Bonferroni correction was used. Results: Upon statistical analysis the root conditioning agents used in this study were found to be effective in removing the smear layer, uncovering and widening the dentin tubules and unmasking the dentin collagen matrix. Conclusion: Tetracycline HCl was found to be the best root conditioner among the three agents used.

  15. Direct and indirect fluorescent detection of tetracyclines using dually emitting carbon dots

    International Nuclear Information System (INIS)

    Qu, Fei; Sun, Zhe; Liu, Dongya; Zhao, Xianen; You, Jinmao

    2016-01-01

    The authors describe dual-emission carbon nanodots containing blue emitters (BE; peak emission at 385 nm under 315 nm excitation) and yellow emitters (YE; peak emission at 530 nm under 365 nm excitation), and how they can be applied to direct and indirect determination of tetracyclines (TCs). The direct detection scheme is based on the finding that tetracycline (TET), oxytetracycline, chlortetracycline and doxycycline quench the two emissions of the carbon dots. While direct determination is rapid and convenient, it cannot differentiate between TCs. The indirect detection scheme, in contrast, is based on the finding that Al (III) ions enhance the fluorescence of the YE in the carbon dots, and that they cause a blue shift in emission. It is, however, known that TET forms a strong complex with Al (III), and this can inhibit the interaction between Al (III) and the YE, so that the fluorescence of YE is not enhanced and blue-shifted by Al (III) in the presence of TET. This finding is exploited in a fluorescence turn-on/off assay for TET that can distinguish TET from other TCs. The linear range of indirect determination for TET extends from 1 nM to 30 μM, and the limit of detection is 0.52 nM. The indirect method was successfully applied to the determination of TET in spiked milk, fish and pork, and recoveries ranged from 91.7 to 102 %. (author)

  16. Effects of a mixture of tetracyclines to Lemna gibba and Myriophyllum sibiricum evaluated in aquatic microcosms

    Energy Technology Data Exchange (ETDEWEB)

    Brain, Richard A [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Wilson, Christian J [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Johnson, David J [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Sanderson, Hans [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Bestari, Ketut [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Hanson, Mark L [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Sibley, Paul K [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Solomon, Keith R [Centre for Toxicology, Department of Environmental Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada)

    2005-12-15

    The impact of a mixture of oxytetracycline, chlortetracycline, tetracycline and doxycycline on Myriophyllum sibiricum and Lemna gibba was investigated using fifteen 12,000-L microcosms (k = 5, n = 3). Significant concentration-response relationships were only found for M. sibiricum, where dry mass was 69, 47, 30, and 7% of controls at respective treatment concentrations of 0.080, 0.218, 0.668, and 2.289 {mu}mol/L. Somatic endpoints were strongly and negatively correlated with percent light transmission, except plant length, which was positively correlated. Treated microcosms experienced a reduction in the percent of surface irradiance penetrating the water column as high as 99.8% at a depth of 70 cm, relative to controls. Position relative to the water column was likely responsible for the differential effects observed between floating (L. gibba) and submerged (M. sibiricum) species of macrophytes. A hazard quotient assessment of the lowest EC{sub 10} value indicated significant risk, exceeding the critical HQ value, but not the lowest EC{sub 25} value. - Mixtures of tetracycline antibiotics pose a risk to submerged but not floating aquatic plants.

  17. Determination of Tetracycline and Fluoroquinolone Antibiotics at Trace Levels in Sludge and Soil

    Directory of Open Access Journals (Sweden)

    Marie-Virginie Salvia

    2015-01-01

    Full Text Available This work describes the development of a sensitive analytical method to determine simultaneously traces of tetracycline and fluoroquinolone antibiotics in sludge and soil, based on PLE extraction, followed by SPE purification and finally an analysis by LC-MS/MS. Recoveries were greater than 87% in the case of fluoroquinolones and between 25.4 and 41.7% for tetracyclines. Low relative standard deviations (<15% were obtained in both matrices. The limits of quantification were comprised between 1.1 and 4.6 ng/g and between 5 and 20 ng/g in soil and sludge, respectively. The method was then successfully applied to the analysis of the target antibiotics in sludge as well as soil that received spreading. The substances most frequently found and with the highest levels were fluoroquinolones with concentrations exceeding 1,000 ng/g in several samples of sludge and up to 16 ng/g in soil.

  18. Identification of rare earth elements by their fluorescence complexes with tetracycline

    International Nuclear Information System (INIS)

    Zanotti-Cavazzoni, J.C.; Boveda V, J.C.; Abrao, A.

    1994-01-01

    A procedure for identification of rare earth elements (REE) based on the complex formation with tetracycline (TC) and visual observation under ultraviolet light is described. One micro drop of REE chloride is placed over the filter paper impregnated with tetracycline and previously dried before use. After dried (30-60 O C) the paper is examined under the UV light. In a second procedure for the identification of mixture of REE a drop of the analyte is added over a filter paper strip impregnated with TC followed by a chromatographic development using a 2:1:1:1 (vol/vol) ethanol, acetone, ether and 1% acetic acid mixture of pH 5,8. After dried, the strip is observed under UV light. Sc, Y, La, Dy, Ho and Lu exhibited high yellow fluorescence; Gd, Tm and Yb a weak yellow; Ce an intense violet; Pr, ND, Sm and Tb violet: Eu a high red fluorescence and Er a violet brown wish, not well defined. It is possible to identify for instance 0.3 ug Ce (concentration 6 mg/L) and 0.2 ug Er (concentration 6 mg/L). Preliminary experiments indicated that those REE-TC chelates can be used for the identification and determination of the REE by spectro fluorimetry. (author). 30 refs

  19. Mark-recapture using tetracycline and genetics reveal record-high bear density

    Science.gov (United States)

    Peacock, E.; Titus, K.; Garshelis, D.L.; Peacock, M.M.; Kuc, M.

    2011-01-01

    We used tetracycline biomarking, augmented with genetic methods to estimate the size of an American black bear (Ursus americanus) population on an island in Southeast Alaska. We marked 132 and 189 bears that consumed remote, tetracycline-laced baits in 2 different years, respectively, and observed 39 marks in 692 bone samples subsequently collected from hunters. We genetically analyzed hair samples from bait sites to determine the sex of marked bears, facilitating derivation of sex-specific population estimates. We obtained harvest samples from beyond the study area to correct for emigration. We estimated a density of 155 independent bears/100 km2, which is equivalent to the highest recorded for this species. This high density appears to be maintained by abundant, accessible natural food. Our population estimate (approx. 1,000 bears) could be used as a baseline and to set hunting quotas. The refined biomarking method for abundance estimation is a useful alternative where physical captures or DNA-based estimates are precluded by cost or logistics. Copyright ?? 2011 The Wildlife Society.

  20. RECONSTRUCTION OF CALCINED Zn -Al LAYERED DOUBLE HYDROXIDES DURING TETRACYCLINE ADSORPSION

    Directory of Open Access Journals (Sweden)

    G. M. Starukh

    2015-12-01

    Full Text Available Zn-Al mixed oxides containing ZnO different degree crystallinity were obtained by calcinations of Zn-Al layered double hydroxides (LDHs. The reconstruction of calcined Zn-Al LDHs has been performed under stirring in aqueous suspensions. The assynthesized LDHs, its decomposition products, as well as the reconstructed solids upon hydration were characterized by XRD, N2adsorption, differential and thermal gravimetric analysis. It was found that the ability of Zn-Al LDHs to recover a layered structure under the hydration of mixed oxides depends on the degree of ZnO crystallinity. The partial reconstruction of Zn-Al layered structure occurs in tetracycline solutions irrespective to the degree of ZnO crystallinity in calcined LDHs. Calcined Zn-Al LDHs demonstrate the higher adsorption capacity to tetracycline in comparison with as-prepared Zn-Al LDHs. The adsorption of TC on calcined and uncalcined ZnAl LDHs occurs on the centers of one particular type. It is suggested that surface complexation of the A-ring ligand of TC with Al-OH centers takes place.

  1. Effects of a mixture of tetracyclines to Lemna gibba and Myriophyllum sibiricum evaluated in aquatic microcosms

    International Nuclear Information System (INIS)

    Brain, Richard A.; Wilson, Christian J.; Johnson, David J.; Sanderson, Hans; Bestari, Ketut; Hanson, Mark L.; Sibley, Paul K.; Solomon, Keith R.

    2005-01-01

    The impact of a mixture of oxytetracycline, chlortetracycline, tetracycline and doxycycline on Myriophyllum sibiricum and Lemna gibba was investigated using fifteen 12,000-L microcosms (k = 5, n = 3). Significant concentration-response relationships were only found for M. sibiricum, where dry mass was 69, 47, 30, and 7% of controls at respective treatment concentrations of 0.080, 0.218, 0.668, and 2.289 μmol/L. Somatic endpoints were strongly and negatively correlated with percent light transmission, except plant length, which was positively correlated. Treated microcosms experienced a reduction in the percent of surface irradiance penetrating the water column as high as 99.8% at a depth of 70 cm, relative to controls. Position relative to the water column was likely responsible for the differential effects observed between floating (L. gibba) and submerged (M. sibiricum) species of macrophytes. A hazard quotient assessment of the lowest EC 10 value indicated significant risk, exceeding the critical HQ value, but not the lowest EC 25 value. - Mixtures of tetracycline antibiotics pose a risk to submerged but not floating aquatic plants

  2. Photoproducts of tetracycline and oxytetracycline involving self-sensitized oxidation in aqueous solutions: Effects of Ca2+ and Mg2+

    Institute of Scientific and Technical Information of China (English)

    Yong Chen; Hua Li; Zongping Wang; Tao Tao; Chun Hu

    2011-01-01

    Tetracyclines constitute one of the most important antibiotic families and represent a classic example of phototoxicity.The photoproducts of tetracyclines and their parent compounds have potentially adverse effects on natural ecosystem.In this study,the self-sensitized oxidation products of tetracycline (TC) and oxytetracycline (OTC) were determined and the effects of Ca2+ and Mg2+on self-sensitized degradation were investigated.The Ca2+ and Mg2+ in the natural water sample accounted for enhancement (pH 7.3)and inhibition (pH 9.0) of photodegradation of TC and OTC due to the formation of metal-ions complexes.The formation of Mg2+ complexes was unfavorable for the photodegradation of the tetracyclines at both pH values.In contrast,the Ca2+ complexes facilitated the attack of singlet oxygen (1O2) arising from self-sensitization at pH 7.3 and enhanced TC photodegradation.For the first time,selfsensitized oxidation products of TC and OTC were verified by quenching experiments and detected by LC/ESI-DAD-MS.The products had a nominal mass 14 Da higher than the parent drugs (designated M+14),which resulted from the 1O2 attack of the dimethylamino group on the C-4 atom of the tetracyclines.The presence of Ca2+ and Mg2+ also affected the generation of M+14 due to the formation of metal-ions complexes with TC and OTC.The findings suggest that the metal-ion complexation has significant impact on the selfsensitized oxidation processes and the photoproducts of tetracyclines.

  3. Comparison of the efficacy of ethylenediaminetetraacetic acid and tetracycline hydrochloride as root conditioning agents: An in vitro study

    Directory of Open Access Journals (Sweden)

    Tarun Nanda

    2012-01-01

    Full Text Available Objective: Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. Various root conditioning agents have been recommended as an adjunct to mechanical root surface debridement to expose dentin collagen and cementum bound proteins. The aim of the present in vitro study was to compare the efficacy of ethylenediaminetetraacetic acid (EDTA and tetracycline hydrochloride (HCl as root conditioning agents on planed root surfaces. Materials and Methods: A total of 20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planed. The teeth were sectioned and specimens were divided into two groups - Group I and II. Group I dentin specimens were treated with EDTA and Group II specimens were treated with tetracycline HCl solution at a concentration of 10% by active burnishing technique for 3 min. The root surface samples were then examined by scanning electron microscope. Results: The results of this study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline when compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl. Conclusion: The results of in vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in vivo importance of EDTA and tetracycline HCL as root conditioners.

  4. Tetracycline as local drug delivery in treatment of chronic periodontitis: A systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Prasad Shyamrajan Nadig

    2016-01-01

    Full Text Available Background: The aim of the present meta-analysis is to determine the efficacy of tetracycline group of antibiotics as local drug delivery agents in the treatment of chronic periodontitis. Materials and Methods: MEDLINE, EBSCO, Cochrane database, and Google Scholar were used to identify studies in English published up to January 31, 2017. An additional hand search of relevant journals and of the bibliographies of the paper identified was also performed. Articles retrieved were screened using specific inclusion criteria by two independent reviewers. Randomized control trials investigating the effect of tetracycline group of antibiotics as local drug delivery agents in chronic periodontitis were included in the study. Results: Ten relevant articles were selected for the meta-analysis, of which five articles were retrieved after electronic search, three articles were included after hand search, and two unpublished articles were included. The number of patients in studies ranged from 13 to 140 sites with mean age ranging from 20 to 75. A total of 588 sites were treated using tetracycline group of antibiotics as local drug delivery agents in the treatment of chronic periodontitis. The meta-analysis showed standard difference in mean −1.02 mm (95% confidence interval [CI] 0.28, 1.75 for clinical gain in attachment in favor of tetracycline group. Standard difference in mean for probing depth (PD was 1.20 mm (95% CI 0.57, 1.87 in tetracycline group. Conclusion: The results of this meta-analysis showed a significant improvement in periodontal parameters such as CAL, PD, and sulcular bleeding index in favor of tetracycline as local drug delivery compared to placebo.

  5. A sampling and metagenomic sequencing-based methodology for monitoring antimicrobial resistance in swine herds

    DEFF Research Database (Denmark)

    Munk, Patrick; Dalhoff Andersen, Vibe; de Knegt, Leonardo

    2016-01-01

    Objectives Reliable methods for monitoring antimicrobial resistance (AMR) in livestock and other reservoirs are essential to understand the trends, transmission and importance of agricultural resistance. Quantification of AMR is mostly done using culture-based techniques, but metagenomic read...... mapping shows promise for quantitative resistance monitoring. Methods We evaluated the ability of: (i) MIC determination for Escherichia coli; (ii) cfu counting of E. coli; (iii) cfu counting of aerobic bacteria; and (iv) metagenomic shotgun sequencing to predict expected tetracycline resistance based...... cultivation-based techniques in terms of predicting expected tetracycline resistance based on antimicrobial consumption. Our metagenomic approach had sufficient resolution to detect antimicrobial-induced changes to individual resistance gene abundances. Pen floor manure samples were found to represent rectal...

  6. Antibiotic resistance of staphylococci from humans, food and different animal species according to data of the Hungarian resistance monitoring system in 2001.

    Science.gov (United States)

    Kaszanyitzky, Eva J; Jánosi, Sz; Egyed, Zsuzsanna; Agost, Gizella; Semjén, G

    2003-01-01

    Based on data of the Hungarian resistance monitoring system the antibiotic resistance of Staphylococcus strains of human and animal origin was studied. No methicillin-resistant staphylococci harbouring mecA gene were isolated from animals in 2001. Penicillin resistance, mediated by penicillinase production, was the most frequent among Staphylococcus aureus strains isolated from humans (96%), from bovine mastitis (55%), from foods (45%) and from dogs. In staphylococci isolated from animals low resistance percentages to aminoglycosides (0-2%), fluoroquinolones (0.5-3%) and sulphonamides (0.5-4%) were found but in strains isolated humans these figures were higher (1-14%, 5-18% and 3-31%, respectively). The most frequent antibiotic resistance profiles of strains isolated from animals and food were penicillin/tetracycline, penicillin/lincomycin and penicillin/lincomycin/tetracycline. Penicillin/tetracycline resistance was exhibited by strains from mastitis (3), samples from the meat industry (31), poultry flocks (1), poultry industry (1), noodle (1) and horses (2). Penicillin/lincomycin resistance was found in 10 Staphylococcus strains from mastitis, 1 from the dairy industry, 1 from the meat industry and 6 from dogs. Isolates from mastitis (2), from the dairy industry (2), from pigs (1), from the meat industry (1) and from poultry (1) harboured penicillin/lincomycin/tetracycline resistance pattern. Multiresistant strains were usually isolated only from one and sometimes from two animal species; therefore, the spread of defined resistant strains (clones) among different animal species could not be demonstrated. These results also suggest that the transfer of antibiotic resistance of S. aureus from animals to humans probably occurs less frequently than is generally assumed.

  7. Antibiotic-Impregnated Central Venous Catheters Do Not Change Antibiotic Resistance Patterns.

    Science.gov (United States)

    Turnbull, Isaiah R; Buckman, Sara A; Horn, Christopher B; Bochicchio, Grant V; Mazuski, John E

    2018-01-01

    Antibiotic-impregnated central venous catheters (CVCs) decrease the incidence of infection in high-risk patients. However, use of these catheters carries the hypothetical risk of inducing antibiotic resistance. We hypothesized that routine use of minocycline and rifampin-impregnated catheters (MR-CVC) in a single intensive care unit (ICU) would change the resistance profile for Staphylococcus aureus. We reviewed antibiotic susceptibilities of S. aureus isolates obtained from blood cultures in a large urban teaching hospital from 2002-2015. Resistance patterns were compared before and after implementation of MR-CVC use in the surgical ICU (SICU) in August 2006. We also compared resistance patterns of S. aureus obtained in other ICUs and in non-ICU patients, in whom MR-CVCs were not used. Data for rifampin, oxacillin, and clindamycin were available for 9,703 cultures; tetracycline resistance data were available for 4,627 cultures. After implementation of MR-CVC use in the SICU, rifampin resistance remained unchanged, with rates the same as in other ICU and non-ICU populations (3%). After six years of use of MR-CVCs in the SICU, the rate of tetracycline resistance was unchanged in all facilities (1%-3%). The use of MR-CVCs was not associated with any change in S. aureus oxacillin-resistance rates in the SICU (66% vs. 60%). However, there was a significant decrease in S. aureus clindamycin resistance (59% vs. 34%; p resistance of S. aureus isolates to rifampin or tetracyclines.

  8. Phenotypic and genotypic antimicrobial resistance and virulence genes of Salmonella enterica isolated from pet dogs and cats

    Science.gov (United States)

    Srisanga, Songsak; Angkititrakul, Sunpetch; Sringam, Patcharee; Le Ho, Phuong T.; Vo, An T. T.

    2017-01-01

    Salmonella enterica isolates (n = 122), including 32 serotypes from 113 dogs and 9 cats, were obtained from household dogs (n = 250) and cats (n = 50) during 2012–2015. The isolates were characterized by serotyping, antimicrobial resistance phenotyping and genotyping, and virulence gene screening. Serovars Weltevreden (15.6%) and Typhimurium (13.9%) were the most common. The majority (43%) of the isolates were multidrug resistant. The dog isolates (12.3%) harbored class 1 integrons, of which the dfrA12-aadA2 cassette was most frequent (66.7%). The only class integron in serovar Albany was located on a conjugative plasmid. Two ESBL-producing isolates (i.e., a serovar Krefeld and a serovar Enteritridis) carried blaTEM and blaCTX-M, and the blaTEM gene in both was horizontally transferred. Of the plasmid-mediated quinolone resistance genes tested, only qnrS (4.9%) was detected. Most Salmonella isolates harbored invA (100%), prgH (91.8%), and sipB (91%). Positive associations between resistance and virulence genes were observed for blaPSE-1/orgA, cmlA/spaN, tolC, and sul1/tolC (p resistance and virulence genes and that antimicrobial use in companion animals may select for the examined Salmonella virulence factors. PMID:27586467

  9. Tetracycline removal and effect on the formation and degradation of extracellular polymeric substances and volatile fatty acids in the process of hydrogen fermentation.

    Science.gov (United States)

    Hou, Guangying; Hao, Xiaoyan; Zhang, Rui; Wang, Jing; Liu, Rutao; Liu, Chunguang

    2016-07-01

    Many research indicate antibiotics show adverse effect on methane fermentation, while few research focus on their effect on hydrogen fermentation. The present study aimed to gain insight of the effect of antibiotics on hydrogen fermentation with waste sludge and corn straw as substrate. For this purpose, tetracycline, as a model, was investigated with regard to tetracycline removal, hydrogen production, interaction with extracellular polymeric substances (EPSs) of substrate and volatile fatty acids (VFAs) on concentration and composition. Results show that tetracycline could be removed efficiently by hydrogen fermentation, and relative low-dose tetracycline (200mg/l) exposure affects little on hydrogen production. While tetracycline exposure could change hydrogen fermentation from butyric acid-type to propionic acid-type depending on tetracycline level. Based upon three-dimensional excitation-emission matrix fluorescence spectroscopy and UV-vis tetracycline changed the component and content of EPSs, and static quenching was the main mechanism between EPSs with tetracycline. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Transfer and Persistence of a Multi-Drug Resistance Plasmid in situ of the Infant Gut Microbiota in the Absence of Antibiotic Treatment

    Directory of Open Access Journals (Sweden)

    Heidi Gumpert

    2017-09-01

    Full Text Available The microbial ecosystem residing in the human gut is believed to play an important role in horizontal exchange of virulence and antibiotic resistance genes that threatens human health. While the diversity of gut-microorganisms and their genetic content has been studied extensively, high-resolution insight into the plasticity, and selective forces shaping individual genomes is scarce. In a longitudinal study, we followed the dynamics of co-existing Escherichia coli lineages in an infant not receiving antibiotics. Using whole genome sequencing, we observed large genomic deletions, bacteriophage infections, as well as the loss and acquisition of plasmids in these lineages during their colonization of the human gut. In particular, we captured the exchange of multidrug resistance genes, and identified a clinically relevant conjugative plasmid mediating the transfer. This resistant transconjugant lineage was maintained for months, demonstrating that antibiotic resistance genes can disseminate and persist in the gut microbiome; even in absence of antibiotic selection. Furthermore, through in vivo competition assays, we suggest that the resistant transconjugant can persist through a fitness advantage in the mouse gut in spite of a fitness cost in vitro. Our findings highlight the dynamic nature of the human gut microbiota and provide the first genomic description of antibiotic resistance gene transfer between bacteria in the unperturbed human gut. These results exemplify that conjugative plasmids, harboring resistance determinants, can transfer and persists in the gut in the absence of antibiotic treatment.

  11. Antimicrobial growth promoter ban and resistance to macrolides and vancomycin in enterococci from pigs

    DEFF Research Database (Denmark)

    Boerlin, P.; Wissing, A.; Aarestrup, Frank Møller

    2001-01-01

    Ninety-six enterococcus isolates from fecal samples of pigs receiving tylosin as an antimicrobial growth promoter and 59 isolates obtained in the same farms 5 to 6 months after the ban of antimicrobial growth promoters in Switzerland were tested for susceptibility to nine antimicrobial agents....... A clear decrease in resistance to macrolides, lincosamides, and tetracycline was visible after the ban. Vancomycin-resistant Enterococcus faecium belonged to the same clonal lineage as vancomycin-resistant isolates previously isolated from Danish pigs....

  12. Antibiotic-resistance of Escherichia coli isolates from stored pig slurry

    OpenAIRE

    Silva, F.F.P.; Santos, M.; Schmidt, Veronica

    2008-01-01

    The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%), nalidixic acid (64%), ampicilin (41%), sulfamethoxazole/trimethoprin (36%), sulfonamide (34%), cloranphenicol (274%), ciprofloxacin (19%), cefaclor (16%), streptomicyn (7.3%), neomicyn (1%), amoxacil...

  13. Resistência antimicrobiana em Salmonella Enteritidis isoladas de amostras clínicas e ambientais de frangos de corte e matrizes pesadas Antimicrobial resistance in Salmonella Enteritidis isolated from clinical and environmental broiler chickens and breeders broiler

    Directory of Open Access Journals (Sweden)

    A.R. Ribeiro

    2008-10-01

    Full Text Available The antimicrobial resistance of Salmonella Enteritidis strains isolated from clinical and environmental poultry samples in the Southern Brazil during the years of 1999, 2000 and 2001 was evaluated. Among the 79 isolated samples, 64 (81% were resistant to at least one of the antimicrobial agents tested, showing 22 different resistance patterns. Tetracycline showed the highest percentage (64,5% of resistance among the antimicrobial agents used. Resistance to drugs at different levels was found as the following: ampicillin (1.2%, kanamycin (1.2%, ciprofloxacin (2.5%, enrofloxacin (8.8%, gentamicin (21.5%, streptomycin (20.2%, nitrofurantoin (26.6%, and nalidixic acid (30.4%. None of the S. Enteritidis strains were resistant to chloramphenicol, norfloxacin, and polimycin B. Among the 64 S. Enteritidis strains that showed resistance, 43 (67.2% were resistant to two or more antimicrobial agents. Twenty-one (32.8% strains were resistant to only one of the antimicrobial agents, 14 to tetracycline, three to nalidixic acid, three to nitrofurantoin, and one to gentamycin. These antimicrobial resistance levels suggest a high occurrence of tetracycline resistant S. Enteritidis strains and resistance to two or more antimicrobial agents.

  14. Prevalence of beta-lactams resistance among Escherichia coli clinical isolates from a hospital in Algiers.

    Science.gov (United States)

    Messai, Y; Benhassine, T; Naim, M; Paul, G; Bakour, R

    2006-06-01

    A high prevalence of beta-lactams resistance among Enterobacteriaceae have been reported worldwide; however, there are not sufficient data on this issue in Algeria. beta-Lactams susceptibility of 203 Escherichia coli clinical isolates was determined by agar diffusion method, and production of extended-spectrum beta-lactamases (ESBL) was screened by double-disk synergy test. This analysis showed five well-defined phenotypes: 1) 62 isolates (30.5%) were susceptible to all beta-lactams; 2) 135 isolates (66.5%) presented a broad-spectrum beta-lactamases phenotype (BSBL); 3) three isolates (1.5%) were defined as producing ESBLs; 4) two isolates (1%) were AmpC cephalosporinase producers; and 5) one isolate (0.5%) presented a phenotype of cell-decreased permeability to beta-lactams. Isoelectric focusing revealed beta-lactamases with isolectric points of 5.4 or 7.6 for isolates with BSBL phenotype; approximately 9.0 for two ESBL isolates; 5.4, 7.6 and approximately 9.0 for the remaining ESBL isolate; and 5.4 and approximately 9.0 for the AmpC isolates. The cefotaxime hydrolysis corresponds to the basic bands with an isoelectric point of approximately 9.0. Conjugation assay showed transfer of penicillinase and AmpC resistance phenotypes and their corresponding beta-lactamases to recipient E. coli BM21 in association with plasmids of 71.4 kb for the AmpC isolates and from 40-56 kb for penicillinase isolates. This result showed that the AmpC phenotype is plasmid mediated. ESBL isolates were found not to transfer their resistance through conjugation experiment. Polymerase chain reaction (PCR) experiments using primers specific to blaTEM, blaAmpC and blaCTX-M genes showed specific amplification with blaCTX-M primer for two ESBL isolates; blaTEM and blaCTX-M for the remaining ESBL isolate; and blaTEM and blaAmpC for the AmpC isolates and their corresponding transconjugants. The study showed a high rate of isolates producing penicillinase, and low frequencies of AmpC and ESBL

  15. Modulation of cytokine and cytokine receptor/antagonist by treatment with doxycycline and tetracycline in patients with dengue fever.

    Science.gov (United States)

    Castro, J E Z; Vado-Solis, I; Perez-Osorio, C; Fredeking, T M

    2011-01-01

    Dengue virus infection can lead to dengue fever (DF) or dengue hemorrhagic fever (DHF). Disease severity has been linked to an increase in various cytokine levels. In this study, we evaluated the effectiveness of doxycycline and tetracycline to modulate serum levels of IL-6, IL-1B, and TNF and cytokine receptor/receptor antagonist TNF-R1 and IL-1RA in patients with DF or DHF. Hospitalized patients were randomized to receive standard supportive care or supportive care combined with doxycycline or tetracycline therapy. Serum cytokine and cytokine receptor/antagonist levels were determined at the onset of therapy and after 3 and 7 days. Cytokine and cytokine receptor/antagonist levels were substantially elevated at day 0. IL-6, IL-1β, and TNF remained at or above day 0 levels throughout the study period in untreated patients. Treatment with tetracycline or doxycycline resulted in a significant decline in cytokine levels. Similarly, IL-1RA and TNF-R1 serum concentrations were elevated at baseline and showed a moderate increase among untreated patients. Both drugs resulted in a significant rise in IL-1Ra levels by day 3 in patients. In contrast, treatment did not affect a similar result for TNF-R1. When compared to the control group, however, a significant rise post-treatment was seen upon intragroup analysis. Further analysis demonstrated that doxycycline was significantly more effective at modulating cytokine and cytokine receptor/antagonist levels than tetracycline.

  16. Detection of acute myocardial infarction in spontaneously hypertensive rats by /sup 99m/Tc-Pyrrolidino methyl tetracycline

    Energy Technology Data Exchange (ETDEWEB)

    Zmbova, B; Tadzer, I; Stakic, D; Bogdanova, V; Stojanova, D

    1983-01-01

    The myocardial infarct induced by isoproterenol in spontaneously hypertensive rats accumulates higher activities of /sup 99/sup(m)Tc-PM tetracycline compared with the cardiac infarct in normotensive rats caused by the same method. The isoproterenol model of the myocardial necrosis was induced in intact rats without opening the thorax and is a convenient method for experimental radioisotope studies.

  17. Ionic treatment for removal of sulfonamide and tetracycline classes of antibiotic

    International Nuclear Information System (INIS)

    Choi, Keun-Joo; Son, Hee-Jong; Kim, Seung-Hyun

    2007-01-01

    Self-decomposition and removal of antibiotics by ionic treatment was evaluated in this study. Seven sulfonamide classes (SA) and seven tetracycline classes (TA) of antibiotic were selected for this purpose. According to this study, self-decomposition of SAs and TAs was slow, and a considerable amount of antibiotics still remained after 15 days. Ionic treatment was effective for removal of SAs and TAs, but organic interference was observed. When dissolved organic (DOC) was present in raw water, the removal performance of antibiotics generally deteriorated due to competition with organics. SAs and TAs, which were present in ionic form at neutral pH, were removed through ion exchange. Their removal efficiencies were closely related to their chemical structure. Antibiotics with stronger electronegativity were easier to remove by ionic treatment. Equilibrium equations for removal of SAs and TAs by ionic treatment were also presented

  18. Symptomatic hepatic cyst in a child: treatment with single-shot injection of tetracycline hydrochloride

    International Nuclear Information System (INIS)

    Fabrizzi, Giancarlo; Lanza, Cecilia; Bolli, Valeria; Pieroni, Giovanni

    2009-01-01

    The prevalence of hepatic cysts is 0.1% to 0.5% based on autopsy studies, and 2.5% based on US examinations. Percutaneous therapies are a new alternative to surgery. They include simple percutaneous aspiration, catheter drainage alone, and catheter drainage with sclerotherapy. We present an 11-year-old boy admitted to hospital because of abdominal pain. A diagnosis of simple hepatic cyst was made, which was treated with aspiration and tetracycline hydrochloride solution (5%) injection into the cystic cavity. Complete regression was seen on US and MRI examination at 3 months, with total collapse and deflation of the cyst. The cyst regressed totally, leaving a hyperechoic linear scar on US examination at 1 year. On the basis of the clinical and imaging results obtained, percutaneous sclerotherapy of hepatic cysts can be recommended as the treatment of choice and as a valid alternative to laparoscopy in children. (orig.)

  19. Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

    International Nuclear Information System (INIS)

    Kaczmarek, Malgorzata; Lis, Stefan

    2009-01-01

    A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 x 10 -7 to 2 x 10 -5 mol L -1 of Chlor-TC; 2 x 10 -7 to 2 x 10 -5 mol L -1 of Oxy-TC and 1 x 10 -7 to 3 x 10 -5 mol L -1 of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.

  20. Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Malgorzata [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland); Lis, Stefan [Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60 - 780 Poznan (Poland)

    2009-04-20

    A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Chlor-TC; 2 x 10{sup -7} to 2 x 10{sup -5} mol L{sup -1} of Oxy-TC and 1 x 10{sup -7} to 3 x 10{sup -5} mol L{sup -1} of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey.

  1. Potential for tumor therapy with tritiated tetracycline. Summary evaluation. [Animal tests

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.C.; Wood, P.; Wood, L.L.; Mendelsohn, M.L.

    1976-10-26

    Reports of tetracycline accumulation in human and animal tumors have led a number of investigators to postulate that this drug, if radio-labeled, might have potential as a therapeutic or diagnostic agent. This paper describes attempts to investigate this potential for tritiated tetracycling. The therapeutic studies demonstrated that while a significant reduction in the growth rates of transplanted tumors could be obtained by the administration of heavy doses of TTC relative to uninjected controls, similar reductions were observed in the growth rates of tumors in animals receiving unlabeled TC. In the localization studies in rodents, the concentrations of TTC in normal tissues and tumors were compared and were correlated with the corresponding concentrations of /sup 14/C-thymidine, a measure of proliferative activity.

  2. Bacterial antibiotic resistance levels in Danish farmland as a result of treatment with pig manure slurry

    DEFF Research Database (Denmark)

    Sengeløv, Gitte; Agersø, Yvonne; Halling-Sørensen, B.

    2003-01-01

    Resistance to tetracycline, macrolides and streptomycin was measured for a period of 8 months in soil bacteria obtained from farmland treated with pig manure slurry. This was done by spread plating bacteria on selective media (Luria Bertani (LB) medium supplemented with antibiotics). To account...

  3. Characterization of the europium tetracycline complex as a biomarker for atherosclerosis

    Science.gov (United States)

    Courrol, Lilia C.; da Silva, Mônica N.; Sicchieri, Leticia B.

    2016-04-01

    Atherosclerosis is a narrowing of the arteries caused by an increase of atheromatous plaque: material formed by macrophage cells containing cholesterol and fatty acids, calcium and a variable amount of fibrous connective tissue. The elation between vulnerable plaques and cardiovascular events can be determined using plaque biomarkers. In this work, atherosclerotic plaques stained with different molar ratios of europium, in a potential plaque biomarker, europium tetracycline complex, were studied by fluorescence microscopy. The tetracycline antibiotic used was chlortetracycline. The growth of atherosclerotic plaque was followed during 60 days in New Zealand rabbits divided in two groups: an experimental group (EG), with nine animals and a control group (CG) with three animals. The animals in the EG received a diet with 1% of cholesterol and the animals of GC received a normal diet. The aortic arch of the animals with 60 days were cut in the vertical plane in 6 μm thick slices, which were mounted on glass slides and stained with hematoxylin an eosin and europium chlortetracycline complex (EuCTc). The fluorescence images were obtained exciting the EuCTc absorption band with a filter cube D (BP 355 - 425) and the emission was collected with a LP 470 suppression filter. Light intensity, detector gain and acquisition time were fixed for comparisons. The 20× magnified images were collected with 12 bit (or 4096 gray tones) resolution. The mean value of gray scale for each molar ratio of EuCTc was different, indicating that the complex interacts with the components of atherosclerotic plaque and the best molar ratio was 1.5 EuCTc. These results indicate the potential use of the EuCTc biomarker for atherosclerotic plaque characterization.

  4. Photo-induced fluorescence of magnesium derivatives of tetracycline antibiotics in wastewater samples

    International Nuclear Information System (INIS)

    Pena, A.; Albert-Garcia, J.R.; Silva, L.J.G.; Lino, C.M.; Calatayud, J. Martinez

    2010-01-01

    An analytical strategy, for the determination of tetracyclines (TCs), based on a HPLC system coupled with a photo-reactor followed by post-column derivatization was developed. Higher fluorescence emission after coupling the resulting photo-fragments with magnesium ions was observed for the determination of minocycline (MC), epitetracycline (ETC), tetracycline (TC) and doxycycline (DC). The manifold included a HPLC system with a photo-reactor (PTFE tubing helically coiled around a low-pressure mercury lamp), a mixing T-piece and a fluorescence detector. The derivatization reagent was delivered at 0.5 mL min -1 by a pump. After HPLC separation using a gradient system with a mobile phase containing oxalic acid 0.02 M and acetonitrile, TCs were irradiated for 60 s, and the resulting photo-fragments were mixed with the post-column derivatization reagent, and the magnesium derivatives of TCs were detected by fluorimetry (λ exc 386 nm, λ em 500 nm). The results obtained showed a significant increase of sensitivity due to photodegration of TCs, 45.4%, 37.6% and 25.3% for MC, TC and ETC respectively. For DC an increase of only 1.5% was observed. The developed method was successfully applied to TCs determination in hospital and municipal wastewater samples using solid phase extraction with Oasis HLB cartridges. The LOQs were 0.25, 0.15, 01 and 0.25 μg L -1 for TC, ETC, MC and DC, respectively. The recovery values oscillated between 107.1% and 92.4% for fortification of 2.5 μg L -1 of each antibiotic.

  5. Photo-induced fluorescence of magnesium derivatives of tetracycline antibiotics in wastewater samples

    Energy Technology Data Exchange (ETDEWEB)

    Pena, A., E-mail: apena@ff.uc.pt [Group of Health Surveillance, Center of Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra (Portugal); Albert-Garcia, J.R. [Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia (Portugal); Silva, L.J.G.; Lino, C.M. [Group of Health Surveillance, Center of Pharmaceutical Studies, Faculty of Pharmacy, University of Coimbra (Portugal); Calatayud, J. Martinez [Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia (Portugal)

    2010-07-15

    An analytical strategy, for the determination of tetracyclines (TCs), based on a HPLC system coupled with a photo-reactor followed by post-column derivatization was developed. Higher fluorescence emission after coupling the resulting photo-fragments with magnesium ions was observed for the determination of minocycline (MC), epitetracycline (ETC), tetracycline (TC) and doxycycline (DC). The manifold included a HPLC system with a photo-reactor (PTFE tubing helically coiled around a low-pressure mercury lamp), a mixing T-piece and a fluorescence detector. The derivatization reagent was delivered at 0.5 mL min{sup -1} by a pump. After HPLC separation using a gradient system with a mobile phase containing oxalic acid 0.02 M and acetonitrile, TCs were irradiated for 60 s, and the resulting photo-fragments were mixed with the post-column derivatization reagent, and the magnesium derivatives of TCs were detected by fluorimetry ({lambda}{sub exc} 386 nm, {lambda}{sub em} 500 nm). The results obtained showed a significant increase of sensitivity due to photodegration of TCs, 45.4%, 37.6% and 25.3% for MC, TC and ETC respectively. For DC an increase of only 1.5% was observed. The developed method was successfully applied to TCs determination in hospital and municipal wastewater samples using solid phase extraction with Oasis HLB cartridges. The LOQs were 0.25, 0.15, 01 and 0.25 {mu}g L{sup -1} for TC, ETC, MC and DC, respectively. The recovery values oscillated between 107.1% and 92.4% for fortification of 2.5 {mu}g L{sup -1} of each antibiotic.

  6. Degradation of Tetracyclines in Pig Manure by Composting with Rice Straw

    Science.gov (United States)

    Chai, Rushan; Huang, Lidong; Li, Lingling; Gielen, Gerty; Wang, Hailong; Zhang, Yongsong

    2016-01-01

    A holistic approach was followed for utilizing tetracyclines (TCs)-contaminated pig manure, by composting this with rice straw in a greenhouse for CO2 fertilization and composted residue application. After composting, the composted residues can be applied to cropland as a supplemental source of synthetic fertilizers. The objective of this study was to determine the effect of pig manure-rice straw composting on the degradation of TCs in pig manure. The results showed that greenhouse composting significantly accelerated the degradation of TCs. Contents (150 mg·kg−1) of oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC) in the composting feedstock could be completely removed within 42 days for OTC and TC, and 14 days for CTC. However, in the control samples incubated at 25 °C in the dark, concentrations of OTC, TC and CTC only decreased 64.7%, 66.7% and 73.3%, respectively, after 49 days. The degradation rates of TCs in the composting feedstock were in the order of CTC > TC > OTC. During the composting process, CTC dissipated rapidly with the time required for 50% degradation (DT50) and 90% degradation (DT90) of 2.4 and 7.9 days, but OTC was more persistent with DT50 and DT90 values of 5.5 and 18.4 days. On the basis of the results obtained in this study, it could be concluded that pig manure-rice straw composting in a greenhouse can help to accelerate the degradation of TCs in pig manure and make composted residues safer for field application. This technology could be an acceptable practice for greenhouse farmers to utilize TCs-contaminated pig manure. PMID:26927136

  7. Development of a miniaturised microarray-based assay for the rapid identification of antimicrobial resistance genes in Gram-negative bacteria

    DEFF Research Database (Denmark)

    Batchelor, Miranda; Hopkins, Katie L; Liebana, Ernesto

    2008-01-01

    We describe the development of a miniaturised microarray for the detection of antimicrobial resistance genes in Gram-negative bacteria. Included on the array are genes encoding resistance to aminoglycosides, trimethoprim, sulphonamides, tetracyclines and beta-lactams, including extended-spectrum ...

  8. Molecular characterization of antibiotic resistance in enterococci recovered from seagulls (Larus cachinnans) representing an environmental health problem.

    Science.gov (United States)

    Radhouani, Hajer; Igrejas, Gilberto; Pinto, Luís; Gonçalves, Alexandre; Coelho, Céline; Rodrigues, Jorge; Poeta, Patrícia

    2011-08-01

    Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting.

  9. Sorption and desorption of glyphosate, MCPA and tetracycline and their mixtures in soil as influenced by phosphate.

    Science.gov (United States)

    Munira, Sirajum; Farenhorst, Annemieke

    2017-12-02

    Phosphate fertilizers and herbicides such as glyphosate and MCPA are commonly applied to agricultural land, and antibiotics such as tetracycline have been detected in soils following the application of livestock manures and biosolids to agricultural land. Utilizing a range of batch equilibrium experiments, this research examined the competitive sorption interactions of these chemicals in soil. Soil samples (0-15 cm) collected from long-term experimental plots contained Olsen P concentrations in the typical (13 to 20 mg kg -1 ) and elevated (81 to 99 mg kg -1 ) range of build-up phosphate in agricultural soils. The elevated Olsen P concentrations in field soils significantly reduced glyphosate sorption up to 50%, but had no significant impact on MCPA and tetracycline sorption. Fresh phosphate additions in the laboratory, introduced to soil prior to, or at the same time with the other chemical applications, had a greater impact on reducing glyphosate sorption (up to 45%) than on reducing tetracycline (up to 13%) and MCPA (up to 8%) sorption. The impact of fresh phosphate additions on the desorption of these three chemicals was also statistically significant, but numerically very small namely glyphosate and tetracycline and 3% for MCPA. The presence of MCPA significantly reduced sorption and increased desorption of glyphosate, but only when MCPA was present at concentrations much greater than environmentally relevant and there was no phosphate added to the MCPA solution. Tetracycline addition had no significant effect on glyphosate sorption and desorption in soil. For the four chemicals studied, we conclude that when mixtures of phosphate, herbicides and antibiotics are present in soil, the greatest influence of their competitive interactions is phosphate decreasing glyphosate sorption and the presence of phosphate in solution lessens the potential impact of MCPA on glyphosate sorption. The presence of chemical mixtures in soil solution has an overall greater impact

  10. Emergence of Ciprofloxacin-Resistant Salmonella enterica Serovar Typhi in Italy.

    Directory of Open Access Journals (Sweden)

    Aurora García-Fernández

    Full Text Available In developed countries, typhoid fever is often associated with persons who travel to endemic areas or immigrate from them. Typhoid fever is a systemic infection caused by Salmonella enterica serovar Typhi. Because of the emergence of antimicrobial resistance to standard first-line drugs, fluoroquinolones are the drugs of choice. Resistance to ciprofloxacin by this Salmonella serovar represents an emerging public health issue. Two S. enterica ser. Typhi strains resistant to ciprofloxacin (CIP were reported to the Italian surveillance system for foodborne and waterborne diseases (EnterNet-Italia in 2013. The strains were isolated from two Italian tourists upon their arrival from India. A retrospective analysis of 17 other S. enterica ser. Typhi strains isolated in Italy during 2011-2013 was performed to determine their resistance to CIP. For this purpose, we assayed for susceptibility to antimicrobial agents and conducted PCR and nucleotide sequence analyses. Moreover, all strains were typed using pulsed-field gel electrophoresis to evaluate possible clonal relationships. Sixty-eight percent of the S. enterica ser. Typhi strains were resistant to CIP (MICs, 0.125-16 mg/L, and all isolates were negative for determinants of plasmid-mediated quinolone resistance. Analysis of sequences encoding DNA gyrase and topoisomerase IV subunits revealed mutations in gyrA, gyrB, and parC. Thirteen different clonal groups were detected, and the two CIP-resistant strains isolated from the individuals who visited India exhibited the same PFGE pattern. Because of these findings, the emergence of CIP-resistant S. enterica ser. Typhi isolates in Italy deserves attention, and monitoring antibiotic susceptibility is important for efficiently managing cases of typhoid fever.

  11. Multidrug-resistant Streptococcus pneumoniae isolates from healthy Ghanaian preschool children

    DEFF Research Database (Denmark)

    Dayie, Nicholas Tete Kwaku Dzifa; Arhin, Reuben E.; Newman, Mercy J.

    2015-01-01

    in a previous study, to six antimicrobials was determined by disk diffusion test. Overall, 90.4% of isolates were intermediate penicillin resistant, 99.1% were trimethoprim resistant, 73.0% were tetracycline resistant, and 33.9% were sulfamethoxazole resistant. Low resistance was recorded for erythromycin (2...... of this study was to determine the antibiogram of S. pneumoniae recovered from Ghanaian children younger than six years of age and to what extent resistances were due to the spread of certain sero- and multilocus sequence typing (MLST) types. The susceptibility of 115 pneumococcal isolates, recovered...

  12. Resistance to non-quinolone antimicrobials in commensal Escherichia coli isolates from chickens treated orally with enrofloxacin.

    Science.gov (United States)

    Jurado, Sonia; Medina, Alberto; de la Fuente, Ricardo; Ruiz-Santa-Quiteria, José A; Orden, José A

    2015-11-01

    The aim of the present study was evaluate how oral administration of enrofloxacin affected the frequency of resistance to different antimicrobials in commensal Escherichia coli isolates from healthy chickens. A further objective of this study was to characterize the mechanisms of resistance in these isolates. A trend towards increased resistance to enrofloxacin, doxycycline and amoxicillin of E. coli isolates from chickens after enrofloxacin administration was observed. The increase in the resistance to doxycycline and amoxicillin was probably due to a co-selection of tetracycline and β-lactam resistance genes by the administration of enrofloxacin. The detection of tetM was much higher than expected (50%), which indicates that this gene may play an important role in tetracycline resistance in E. coli from chickens.

  13. THE RESISTANCE TO ANTIBIOTICS IN STRAINS OF E. COLI AND ENTEROCOCCUS SP. ISOLATED FROM RECTAL SWABS OF LAMBS AND CALVES

    Directory of Open Access Journals (Sweden)

    IVANA NOVÁKOVÁ

    2009-10-01

    Full Text Available he aim of this study was to determine the prevalence and antibiotic resistance of enterococcii and E. coli strains isolated from dairy calves and lambs. Susceptibilities of isolated enterococci were tested using the disk diffusion method. The interpretation of inhibition zones around the disks was according to CLSI 2004 Performance standards for antimicrobial susceptibility testing. In our study, all isolates (E. coli and enterococci were multiresistant (100% to tetracycline, streptomycin and compound sulphonamides. Lower levels of resistance to enrofloxacin were noted. Antimicrobial resistance profiles of Enterococcus sp. isolated from lambs indicated that the highest percentage of susceptibility was exhibited to tetracycline (100% and streptomycin (100% and compound sulphonamides (100%. The intermediate resistance was exhibited against compound enrofloxacin (80%. The high frequencies of resistant isolates of Enterococcus sp. from calves were documented in tetracycline (100%, streptomycin (100% and compound sulphonamides (100% and enrofloxacin (50%. The high percentage (compound sulphonamides-100%, tetracycline-100% and streptomycin- 100% of multiresistant E. coli (isolates from dairy calves was noticed. There were no significant correlations between groups.

  14. Cephalosporin resistance in Neisseria gonorrhoeae

    Directory of Open Access Journals (Sweden)

    Manju Bala

    2010-01-01

    Full Text Available Gonorrhea, a disease of public health importance, not only leads to high incidence of acute infections and complications but also plays a major role in facilitating human immunodeficiency virus (HIV acquisition and transmission. One of the major public health needs for gonorrhea control is appropriate, effective treatment. However, treatment options for gonorrhea are diminishing as Neisseria gonorrhoeae have developed resistance to several antimicrobial drugs such as sulfonamides, penicillin, tetracyclines and quinolones. Antimicrobial resistance (AMR surveillance of N. gonorrhoeae helps establish and maintain the efficacy of standard treatment regimens. AMR surveillance should be continuous to reveal the emergence of new resistant strains, monitor the changing patterns of resistance, and be able to update treatment recommendations so as to assist in disease control. Current treatment guidelines recommend the use of single dose injectable or oral cephalosporins. The emergence and spread of cephalosporin resistant and multi drug resistant N. gonorrhoeae strains, represents a worrying trend that requires monitoring and investigation. Routine clinical laboratories need to be vigilant for the detection of such strains such that strategies for control and prevention could be reviewed and revised from time to time. It will be important to elucidate the genetic mechanisms responsible for decreased susceptibility and future resistance. There is also an urgent need for research of safe, alternative anti-gonococcal compounds that can be administered orally and have effective potency, allowing high therapeutic efficacy (greater than 95.0% cure rate.

  15. Diversity and antimicrobial susceptibility of Salmonella enterica serovars isolated from pig farms in Ibadan, Nigeria

    DEFF Research Database (Denmark)

    Fashae, Kayode; Hendriksen, Rene S.

    2014-01-01

    of plasmid-mediated quinolone resistance (PMQR) genes in pigs in Ibadan, Nigeria. Pooled fresh pen floor fecal samples of pigs collected from 31 pig farms were cultured; the Salmonella isolates were serotyped and their antimicrobial susceptibility was determined. PMQR genes were screened by polymerase chain...... Kingston (n = 13; 5.7 %). The most widely distributed serovars among the farms were Salmonella Give (six farms) and Salmonella Elisaberthville (six farms). Resistance to chloramphenicol, sulfonamides, nalidixic acid, streptomycin, and tetracycline ranged from 11.6 % (n = 26) to 22.8 % (n = 51). Resistance....... Other PMQR genes were not detected. Pigs constitute an important source of diverse Salmonella serovars in Ibadan. The isolates were more resistant to old antimicrobials with some multiple resistant. Control measures and regulation of antimicrobials are warranted....

  16. The local transfer of plasmid-mediated human inducible nitric oxide synthase gene with protein-coated metallic stents inhibits intimal hyperplasia following coronary angioplasty in mini-swine model%蛋白涂层支架携带质粒介导的一氧化氮 合酶基因预防冠状动脉球囊扩张后 再狭窄的实验研究

    Institute of Scientific and Technical Information of China (English)

    戴军; 高润霖; 宋来凤; 阮英茆; 陈纪林; 李永力; 孟亮; 唐承君; 史瑞文; 汤键

    2001-01-01

    Objective To assess the effect of local transfer ofplasmid-mediated inducible Nitric Oxide synthase gene using protein-coated metallic stents of inhibiting neointimal hyperplasia after coronary angioplasty. Methods The metallic stent was coated by cross-linked gelatin and mounted on 3.0 mm PTCA balloon,then endotoxin-free ultrapure plasmid pcDNA3hepiNOS was absorbed on the stent. Protein-coated stainless steel stents were used as controls. All stents were implanted into the middle segment of LAD. The ratio of balloon to vessel diameter was 1.1-1.3:1. Results At the 7th day after stenting, RT-PCR and immunohistochemical staining confirmed the expression of iNOS mRNA and presence of its protein at gene transferred vessels (n=2), but there was no expression in remote organs. After 3 months of stenting coronary angiograms showed that there was no restenosis in all animals transferred plasmid pcDNA3hepiNOS(n=5) while restenosis developed in all animals of the control group (n=5). Morphometric analysis showed that lumen diameter loss (0.61±0.30) mm vs (1.58±0.31) mm (P<0.001), residual lumen diameter (1.00±0.51) mm vs (0.36±0.32) mm (P<0.05), neointimal area (1.65±0.83) mm2 vs (2.83±0.83) mm2 (P<0.05), mean percentage of area stenosis (26.45±7.45) mm2 vs (94.2±14.3) mm2 (P<0.001) were significantly less than those in control group. The proportion of the neointimal area to media area(I/M) reduced to 59.84% in pcDNA3hepiNOS group. Conclusions Local plasmid-mediated human iNOS gene transferred with protein-coated metallic stents significantly inhibited intimal hyperplasia,which was usually a causative factor of retenosis after coronary angioplasty, in mini-swine model.%目的 为评价蛋白涂层金属支架携带质粒介导的诱导性一氧化氮合酶(iNOS)基因局部转染血管壁,预防冠状动脉内血管成形术后再狭窄的效果。方法 金属支架涂层为胶联明胶制成。载体为去内毒素纯化pcDNA3。采用标准球囊导管技

  17. Duration of oral tetracycline-class antibiotic therapy and use of topical retinoids for the treatment of acne among general practitioners (GP): A retrospective cohort study.

    Science.gov (United States)

    Barbieri, John S; Hoffstad, Ole; Margolis, David J

    2016-12-01

    Guidelines recommend limiting the duration of oral antibiotic therapy in acne to 3 to 6 months and prescribing concomitant topical retinoids for all patients. We sought to evaluate the duration of therapy with oral tetracyclines and the use of topical retinoids among patients with acne treated primarily by general practitioners in the United Kingdom. We conducted a retrospective cohort study using the Health Improvement Network database. The mean duration of therapy was 175.1 days. Of antibiotic courses, 62% were not associated with a topical retinoid; 29% exceeded 6 months in duration. If all regions were to achieve uses similar to the region with the shortest mean duration of therapy, approximately 3.3 million antibiotic days per year could be avoided in the United Kingdom. The Health Improvement Network does not include information on acne severity and clinical outcomes. Prescribing behavior for oral antibiotics in the treatment of acne among general practitioners is not aligned with current guideline recommendations. Increasing the use of topical retinoids and considering alternative agents to oral antibiotics when appropriate represent opportunities to reduce antibiotic exposure and associated complications such as antibiotic resistance and to improve outcomes in patients treated for acne. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  18. Antimicrobial resistance of fecal Salmonella spp. isolated from all phases of pig production in 20 herds in Alberta and Saskatchewan

    OpenAIRE

    Rosengren, Leigh B.; Waldner, Cheryl L.; Reid‐Smith, Richard J.; Checkley, Sylvia L.; McFall, Margaret E.; Rajíc, Andrijana

    2008-01-01

    Salmonella spp. (n = 468), isolated from the feces of sows, nursery, and grow‐finish pigs in 20 farrow‐to‐finish herds in Alberta and Saskatchewan, were tested for susceptibility to 16 antimicrobials. No resistance was identified to amikacin, amoxicillin‐clavulanic acid, ceftiofur, ceftriaxone, ciprofloxacin or nalidixic acid, and less than 1% of the isolates were resistant to cefoxitin and gentamicin. Isolates were most commonly resistant to tetracycline (35%) and sulfamethoxazole (27%). Ove...

  19. Resistência a antimicrobianos de Escherichia coli isolada de dejetos suínos em esterqueiras

    OpenAIRE

    Silva,F.F.P.; Santos,M.A.A.; Schmidt,V.

    2008-01-01

    The antimicrobial resistance of 96 Escherichia coli strains isolated from a stabilization pond system on a pig-breeding farm was evaluated. Strains were tested for their resistance against 14 antimicrobial using the agar diffusion method. E. coli strains showed resistance to tetracycline (82.3%), nalidixic acid (64%), ampicilin (41%), sulfamethoxazole/trimethoprin (36%), sulfonamide (34%), cloranphenicol (274%), ciprofloxacin (19%), cefaclor (16%), streptomicyn (7.3%), neomicyn (1%), amoxacil...

  20. [Effect of the crystallization conditions of tetracycline base on the properties of the powders and drug forms obtained. The dependence of the degree of dispersion of tetracycline base on the crystallization conditions].

    Science.gov (United States)

    Lin'kov, G I; Zhukovskaia, S A; Dzhabarov, D N; Nabokov, V S

    1977-09-01

    Characteristics of the powder dispersity of tetracycline base samples prepared by directed crystallization with variation of the process conditions were determined by the sedimentation method. It was found that the speed of the solution agitation had the maximum effect on the level and nature of the dispersity. The rate of the solution temperature and pH changing during the crystallization process had also a significant effect at low agitation speed.

  1. Complementation of a pKM101 derivative that decreases resistance to UV killing but increases susceptibility to mutagenesis

    International Nuclear Information System (INIS)

    Langer, P.J.; Perry, K.L.; Walker, G.C.

    1985-01-01

    The drug resistance plasmid pKM101 makes Escherichia coli resistant to the lethal effects of ultraviolet (UV) irradiation and more susceptible to mutagenesis by a variety of agents. The plasmid operon responsible for increasing mutagenesis has been termed mucAB (Mutagenesis, UV and chemical). The authors have isolated a derivative of pKM101 called pGW1975 which makes cells more sensitive to killing by UV but which retains the ability of pKM101 to increase susceptibility to methyl methanesulfonate (MMS) mutagenesis. pGW1975 increases UV mutagenesis less than pKM101 in a uvrA + strain but more than pKM101 in a uvrA - strain. muc - point and insertion mutants of pKM101 and pGW1975 complement to restore the plasmid-mediated: (i) ability to reactivate UV-irradiated phage, (ii) resistance to killing by UV, and (iii) level of susceptibility to UV mutagenesis. They have identified a 2.0 kb region of pKM101 which is responsible for the complementation and which maps counterclockwise of mucAB. (Auth)

  2. Microbial Community Structure of a Leachfield Soil: Response to Intermittent Aeration and Tetracycline Addition

    Directory of Open Access Journals (Sweden)

    David A. Potts

    2013-04-01

    Full Text Available Soil-based wastewater treatment systems, or leachfields, rely on microbial processes for improving the quality of wastewater before it reaches the groundwater. These processes are affected by physicochemical system properties, such as O2 availability, and disturbances, such as the presence of antimicrobial compounds in wastewater. We examined the microbial community structure of leachfield mesocosms containing native soil and receiving domestic wastewater under intermittently-aerated (AIR and unaerated (LEACH conditions before and after dosing with tetracycline (TET. Community structure was assessed using phospholipid fatty acid analysis (PLFA, analysis of dominant phylotypes using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR–DGGE, and cloning and sequencing of 16S rRNA genes. Prior to dosing, the same PLFA biomarkers were found in soil from AIR and LEACH treatments, although AIR soil had a larger active microbial population and higher concentrations for nine of 32 PLFA markers found. AIR soil also had a larger number of dominant phylotypes, most of them unique to this treatment. Dosing of mesocosms with TET had a more marked effect on AIR than LEACH soil, reducing the size of the microbial population and the number and concentration of PLFA markers. Dominant phylotypes decreased by ~15% in response to TET in both treatments, although the AIR treatment retained a higher number of phylotypes than the LEACH treatment. Fewer than 10% of clones were common to both OPEN ACCESS Water 2013, 5 506 AIR and LEACH soil, and fewer than 25% of the clones from either treatment were homologous with isolates of known genus and species. These included human pathogens, as well as bacteria involved in biogeochemical transformations of C, N, S and metals, and biodegradation of various organic contaminants. Our results show that intermittent aeration has a marked effect on the size and structure of the microbial community that develops in

  3. Brugia malayi gene expression in response to the targeting of the Wolbachia endosymbiont by tetracycline treatment.

    Directory of Open Access Journals (Sweden)

    Elodie Ghedin

    2009-10-01

    Full Text Available Brugia malayi, like most human filarial parasite species, harbors an endosymbiotic bacterium of the genus Wolbachia. Elimination of the endosymbiont leads to sterilization of the adult female. Previous biochemical and genetic studies have established that communication with its endobacterium is essential for survival of the worm.We used electron microscopy to examine the effects of antibiotic treatment on Wolbachia cell structure. We have also used microarray and quantitative RT-PCR analyses to examine the regulation of the B. malayi transcripts altered in response to the anti-Wolbachia treatment. Microscopy of worms taken from animals treated with tetracycline for 14 and 21 days (14 d and 21 d demonstrated substantial morphologic effects on the Wolbachia endobacterium by 14 d and complete degeneration of the endobacterial structures by 21 d. We observed upregulation of transcripts primarily encoding proteins involved in amino acid synthesis and protein translation, and downregulation of transcripts involved in cuticle biosynthesis after both 7 d and 14 d of treatment. In worms exposed to tetracycline in culture, substantial effects on endobacteria morphology were evident by day 3, and extensive death of the endobacteria was observed by day 5. In a detailed examination of the expression kinetics of selected signaling genes carried out on such cultured worms, a bimodal pattern of regulation was observed. The selected genes were upregulated during the early phase of antibiotic treatment and quickly downregulated in the following days. These same genes were upregulated once more at 6 days post-treatment.Upregulation of protein translation and amino acid synthesis may indicate a generalized stress response induced in B. malayi due to a shortage of essential nutrients/factors that are otherwise supplied by Wolbachia. Downregulation of transcripts involved in cuticle biosynthesis perhaps reflects a disruption in the normal embryogenic program. This is

  4. The whitening effect of bleaching agents on tetracycline-stained rat teeth.

    Science.gov (United States)

    Shin, D H; Summitt, J B

    2002-01-01

    This study compared the whitening effect of three bleaching agents on the teeth of rats and demonstrated differences in bleaching where dentin was exposed or enamel was thin. Thirty Albino rats were peritoneally injected with tetracycline solution daily for two weeks. Thirty-two disc-shaped specimens were cut from the crowns of incisors removed from sacrificed rats and were irradiated with UV light for 16 hours. Sections were stored in saline. Eight sections served as controls and were not bleached. Three bleaching agents (Opalescence, Rembrandt and Nite White) were applied to eight specimens each, five times a day for two weeks, and images of the sections were recorded at the following times: before bleaching (baseline), day 1, day 3, day 5, day 7, day 9, day 11 and day 14. Mean colors to demonstrate any change (deltaE) from baseline for each time period were as follows: control-9.78 (baseline), 9.17, 9.36, 9.65, 9.40, 9.99, 10.57, 11.36; Opalescence-10.08, (baseline) 7.63, 6.72, 6.04, 5.10, 4.87, 4.89, 4.27; Rembrandt-9.83 (baseline), 11.27, 9.55, 8.36, 7.75, 6.94, 7.11, 7.04; Nite White-10.44 (baseline), 9.92, 7.58, 6.80, 5.45, 5.05, 4.73, 4.01. All bleached teeth were lightened (p<.01). Another 56 tetracycline-stained rat incisors were UV irradiated for three days. Three different penetration depths were tested: penetration through lingual dentin and labial enamel (DN group), penetration through labial enamel only (RE group) and penetration through labial enamel covered with 1.0 mm human enamel (HE group). Specimens were bleached with Opalescence for one hour five times a day for one week or four weeks. A control group of unbleached teeth was also examined. Results (deltaE) were as follows: control--11.67; 1-week DN--13.55; 1-week RE--12.80; 1-week HE--12.07; 4-week DN--7.48; 4-week RE--7.50; 4-week HE--11.69. The color change in the 4-week DN and the 4-week RE groups showed the greatest reduction (p<.01).

  5. Molecular characterization of multidrug-resistant Klebsiella pneumoniae isolates

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    Xiang-hua Hou

    2015-09-01

    Full Text Available Klebsiella pneumoniae is an important cause of healthcare-associated infections worldwide. Selective pressure, the extensive use of antibiotics, and the conjugational transmission of antibiotic resistance genes across bacterial species and genera facilitate the emergence of multidrug-resistant (MDR K. pneumoniae. Here, we examined the occurrence, phenotypes and genetic features of MDR K. pneumoniae isolated from patients in intensive care units (ICUs at the First Affiliated Hospital of Xiamen University in Xiamen, China, from January to December 2011. Thirty-eight MDR K. pneumoniae strains were collected. These MDR K. pneumoniae isolates possessed at least seven antibiotic resistance determinants, which contribute to the high-level resistance of these bacteria to aminoglycosides, macrolides, quinolones and β-lactams. Among these isolates, 24 strains were extended-spectrum β-lactamase (ESBL producers, 2 strains were AmpC producers, and 12 strains were both ESBL and AmpC producers. The 38 MDR isolates also contained class I (28/38 and class II integrons (10/38. All 28 class I-positive isolates contained aacC1, aacC4, orfX, orfX’ and aadA1 genes. β-lactam resistance was conferred through blaSHV (22/38, blaTEM (10/38, and blaCTX-M (7/38. The highly conserved blaKPC-2 (37/38 and blaOXA-23(1/38 alleles were responsible for carbapenem resistance, and a gyrAsite mutation (27/38 and the plasmid-mediated qnrB gene (13/38 were responsible for quinolone resistance. Repetitive-sequence-based PCR (REP-PCR fingerprinting of these MDR strains revealed the presence of five groups and sixteen patterns. The MDR strains from unrelated groups showed different drug resistance patterns; however, some homologous strains also showed different drug resistance profiles. Therefore, REP-PCR-based analyses can provide information to evaluate the epidemic status of nosocomial infection caused by MDR K. pneumoniae; however, this test lacks the power to discriminate some

  6. High prevalence of fluoroq