WorldWideScience

Sample records for genotypes exhibiting resistance

  1. Characteristics of spring wheat genotypes exhibiting high resistance to FHB in terms of their resistance to other fungal diseases

    Directory of Open Access Journals (Sweden)

    Danuta Kurasiak-Popowska

    2016-09-01

    Full Text Available The field experiment was carried out in 2010–2012 at the Dłoń Agricultural Research Station, the Poznań University of Life Sciences, Poland. The study was designed to evaluate the degree of infection by powdery mildew, brown rust, and septoria leaf blotch in 61 spring wheat genotypes differing in their resistance to Fusarium ssp. The vast majority of spring wheat genotypes in the collection of gene resources in the USA defined as resistant to Fusarium ssp. confirmed their resistance under Polish climatic conditions. The B .graminis infection rate of genotypes that are considered to be resistant to Fusarium head blight was high. The resistance ranged from 7 for Sumai 3 (PL2 up to 8.8 for Ning 8331 (in a 9-point scale. Most of the genotypes (56.5% were infected by Puccinia recondita at a level of 1–3 (in a 9-point scale. The genotypes of Sumai 3 exhibited high resistance to septoria leaf blotch, amounting to 1–2 in a 9-point scale; the resistance of Frontana ranged from 1 to 3.5, while the genotypes of Ning were infected by Mycosphaerella graminicola at 5–6.

  2. Resistance of corn genotypes to fall armyworm Spodoptera ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-08-31

    Aug 31, 2016 ... The objective of this study was to evaluate resistance mechanisms in 12 corn genotypes (transgenic hybrids: ..... FAW that fed on GM corn genotypes exhibited lower ... preference for other food types, particularly given the.

  3. Characterization of cowpea genotype resistance to Callosobruchus maculatus

    Directory of Open Access Journals (Sweden)

    Maria de Jesus Passos de Castro

    2013-09-01

    Full Text Available The objective of this work was to characterize the resistance of 50 cowpea (Vigna unguiculata genotypes to Callosobruchus maculatus. A completely randomized design with five replicates per treatment (genotype was used. No-choice tests were performed using the 50 cowpea genotypes to evaluate the preference for oviposition and the development of the weevil. The genotypes IT85 F-2687, MN05-841 B-49, MNC99-508-1, MNC99-510-8, TVu 1593, Canapuzinho-1-2, and Sanzi Sambili show non-preference-type resistance (oviposition and feeding. IT81 D-1045 Ereto and IT81 D-1045 Enramador exhibit antibiosis against C. maculatus and descend from resistant genitors, which grants them potential to be used in future crossings to obtain cowpea varieties with higher levels of resistance.

  4. Differentiation in quinolone resistance by virulence genotype in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Melissa Agnello

    Full Text Available Pseudomonas aeruginosa is a leading pathogen that has become increasingly resistant to the fluoroquinolone antibiotics due to widespread prescribing. Adverse outcomes have been shown for patients infected with fluoroquinolone-resistant strains. The type III secretion system (TTSS is a major virulence determinant during acute infections through the injection of effector toxins into host cells. Most strains exhibit a unique TTSS virulence genotype defined by the presence of either exoS or exoU gene encoding two of the effector toxins, ExoS and ExoU, respectively. Specific TTSS effector genotype has been shown previously to differentially impact virulence in pneumonia. In this study, we examined the relationship between TTSS effector genotype and fluoroquinolone resistance mechanisms in a collection of 270 respiratory isolates. We found that a higher proportion of exoU+ strains were fluoroquinolone-resistant compared to exoS+ strains (63% vs 49%, p = 0.03 despite its lower overall prevalence (38% exoU+ vs 56% exoS+. Results from sequencing the quinolone resistance determining regions (QRDRs of the 4 target genes (gyrA, gyrB, parC, parE indicated that strains containing the exoU gene were more likely to acquire ≥ 2 mutations than exoS+ strains at MICs ≤ 8 µg/ml (13% vs none and twice as likely to have mutations in both gyrA and parC than exoS+ strains (48% vs 24% p = 0.0439. Our findings indicate that P. aeruginosa strains differentially develop resistance-conferring mutations that correlate with TTSS effector genotype and the more virulent exoU+ subpopulation. Differences in mutational processes by virulence genotype that were observed suggest co-evolution of resistance and virulence traits favoring a more virulent genotype in the quinolone-rich clinical environment.

  5. Identification of blast resistance expression in rice genotypes using ...

    African Journals Online (AJOL)

    USER

    2010-06-14

    Jun 14, 2010 ... genotypes were evaluated for resistance to blast disease under induced epiphytotic conditions obtained in the ..... desirable changes in the population through selection ..... that resistance sources are non-allelic for resistance.

  6. Exhibiting eugenics: response and resistance to a hidden history.

    Science.gov (United States)

    Brave, Ralph; Sylva, Kathryn

    2007-01-01

    Human Plants, Human Harvest: The Hidden History of California Eugenics is the first-ever exhibition on the history of eugenics in California. The disappearance of this history for half a century, and the consequent absence of a "collective menory", were the primary factors determining the exhibit's sttrcture and content. Responses to the exhibit confirmed that most visitors "never knew" about this history. The exhibit is described in some detail, with selected imagery from the exhibit reproduced. After the initial exhibition, responses of other museums and foundation officials revealed a continuing resistance to this history being publicly displayed, though the sources of resistance varied.

  7. Genotypic carriers of the obesity-associated FTO polymorphism exhibit different cardiometabolic profiles after an intervention

    Directory of Open Access Journals (Sweden)

    GREICE G. MORAES

    Full Text Available ABSTRACT Background: Children and adolescents with at-risk genotypes (AA/AT of the rs9939609 polymorphism in FTO, a fat mass and obesity-associated gene, may exhibit different cardiometabolic profile responses than subjects with the TT genotype after an interdisciplinary intervention. Methods: The sample consisted of 36 school children from southern Brazil. We used DNA quantitation and real-time polymerase chain reaction (PCR for polymorphism genotyping. We measured anthropometric parameters (body mass index (BMI, waist circumference, hip circumference, waist-hip ratio, body fat percentage and skinfold sum, biochemical parameters (glucose, lipid profile, ultra-sensitive C-reactive protein, uric acid, alanine aminotransferase, aspartate aminotransferase, insulin and adiponectin and blood pressure. The 4-month intervention consisted of physical education classes, nutritional counseling, and postural and oral health counseling. Results: We observed no significant differences among the groups (AA, AT and TT after the intervention. However, we observed improvements in three parameters (waist circumference, hip circumference and C-reactive protein in the AT/AA genotype group and in two parameters (hip circumference and uric acid in the TT genotype group. Conclusions: After an intervention program, carriers of at-risk genotypes for obesity (AA/AT do not exhibit differences in biochemical parameters, blood pressure and anthropometric parameters compared with carriers of the TT genotype.

  8. Genetic diversity in soybean genotypes with resistance to Heterodera glycines

    Directory of Open Access Journals (Sweden)

    Ana Paula Oliveira Nogueira

    2011-01-01

    Full Text Available The purpose of this study was to analyze the genetic diversity among soybean genotypes inoculated with Heteroderaglycines race 3. The experiments were conducted in a greenhouse. In two performance tests of morphological characteristics andresistance to the pathogen, 27 soybean genotypes were assessed. The coefficient of genotypic determination was estimated by themethod of analysis of variance and the genetic diversity analyzed based on dendrograms and optimization method. The estimatedcoefficients of determination indicated a predominantly genetic origin of the genotypic differences in the traits. The genetic variabilitywas maintained in the superior genotypes, which can be used in breeding programs for resistance to soybean cyst nematode

  9. Drug-Susceptible Mycobacterium tuberculosis Beijing Genotype Does Not Develop Mutation-Conferred Resistance to Rifampin at an Elevated Rate

    OpenAIRE

    2003-01-01

    The Mycobacterium tuberculosis Beijing genotype has drawn attention because it is often strongly associated with multidrug-resistant tuberculosis (MDR-TB). A possible reason is that the Beijing strains may have an enhanced capacity to develop drug resistance. In this study, we used the Luria-Delbrück fluctuation test to investigate whether strains of Beijing and non-Beijing genotypes exhibit differences in the acquisition of drug resistance. The M. tuberculosis reference strain H37Rv and 12 f...

  10. 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

    these figures were 67% and 42%, respectively, for the reference strains.Genotyping of tetracycline resistance determinants was performed with primers specific for tet(A–E, H, K–M, O). Strains positive for tet(B), tet(H) and tet(L) were identified, however, in 20 out of 49 tetracycline resistant strains...

  11. Acyl sugars and whitefly (Bemisia tabaci) resistance in segregating populations of tomato genotypes.

    Science.gov (United States)

    Dias, D M; Resende, J T V; Marodin, J C; Matos, R; Lustosa, I F; Resende, N C V

    2016-04-07

    The wild tomato, Solanum pennellii, is an important source of resistance genes against tomato pests. This resistance is due to the presence of acyl sugars (AS), which are allelochemicals that have negative effects on arthropod pests. There are no commercially available tomato cultivars that exhibit significant levels of resistance to arthropod pests. Therefore, this study evaluated resistance to whitefly (Bemisia tabaci) in F2 and F2RC1 tomato genotypes with high AS levels from a cross between Solanum lycopersicum 'Redenção' and the S. pennellii accession, LA-716. Plants were exposed to B. tabaci biotype B at the pre-flowering stage. In both generations, there were significant, negative correlations between AS content and oviposition preference and nymph development. Whitefly exhibited a lower preference for oviposition and produced fewer nymphs in genotypes with high AS levels and the wild parent S. pennellii than in the low AS-level genotypes and Redenção cultivar, demonstrating that the breeding program was effective in transferring resistance to the F2 and F2RC1 generations. RVTA-2010-pl#31 and RVTA-2010-pl#94 in the F2 population are promising genotypes that produced materials with high AS levels in the F2RC1 generation (RVTA-2010-31-pl#177 and RVTA-2010-94-pl#381).

  12. Hepatitis B virus genotypes and lamivudine resistance mutations in Jordan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To investigate and identify prevalent hepatitis B virus (HBV) genotypes and to explore lamivudine-resistant mutations among treated and untreated patients in Jordan.METHODS: A total of 107 cases with chronic hepatitis B were recruited from different medical centers in Jordan. Serological tests were preformed for all cases using a microparticle enzyme immunoassay. HBV Genotyping was performed for 70 cases using Line probe genotyping assay, The YMDD mutations were explored for 20 cases (4 were lamivudine naive) using the INNO-LiPA HBV DR assay.RESULTS: Genotype D was the only detected genotype. A total of 6 YMDD mutations were detected in 5 treated patients (31%) while one mutation was detected in the naive patients. Seventeen percent of cases were positive for HBeAg and had statistically significant higher levels of serum aminotransferases.CONCLUSION: HBV genotype D appears to be the only circulating type in Jordanian patients. The YMDD mutations were detected in 31% of lamivudine-treated cases with similar patterns to those found in the lit-erature. We also found a relatively low prevalence of HBeAg expression among examined cases (17%). Awareness of these serologic, genotypic and resistance patterns might help in the formulation of management plans and for predicting clinical outcomes. Further larger scale studies are needed to confirm our results and to examine possible associations among clinical, serologic, and genetic patterns of HBV infections in Jordan.

  13. Exhibition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    China[Guangzheu] International Trade Fair for Home Textiles Date:March 18th- March 21st,2011 Venue:China Import and Export Fair Complex(Guangzhou,China) Organizers:China National Textile&Apparel Council China Foreign Trade Center(Group) China Home Textile Association China Foreign Trade Guangzhou Exhibition Corp.

  14. Arabidopsis mutant bik1 exhibits strong resistance to Plasmodiophora brassicae

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2016-09-01

    Full Text Available Botrytis-induced kinase1 (BIK1, a receptor-like cytoplasmic kinase, plays an important role in resistance against pathogens and insects in Arabidopsis thaliana. However, it remains unknown whether BIK1 functions against Plasmodiophora brassicae, an obligate biotrophic protist that attacks cruciferous plants and induces gall formation on roots. Here, we investigated the potential roles of receptors FLS2, BAK1 and BIK1 in the infection of P. brassicae cruciferous plants. Wild-type plants, fls2 and bak1 mutants showed typical symptom on roots, and the galls were filled with large quantities of resting spores, while bik1 mutant plants exhibited strong resistance to P. brassicae. Compared with that of the wild-type plants, the root hair and cortical infection rate of bik1 mutant were significantly reduced by about 40-50%. A considerable portion of bik1 roots failed to form typical galls. Even if some small galls were formed, they were filled with multinucleate secondary plasmodia. The bik1 plants accumulated less reactive oxygen species (ROS at infected roots than other mutants and wild-type plants. Exogenous salicylic acid (SA treatment alleviated the clubroot symptoms in wild-type plants, and the expression of the SA signaling marker gene PR1 was significantly increased in bik1. Both sid2 (salicylic acid induction-deficient 2 and npr1-1 (non-expresser of PR genes that regulate systemic acquired resistance (SAR mutants showed increased susceptibility to P. brassicae compared with wild-type plants. These results suggest that the resistance of bik1 to P. brassicae is possibly mediated by SA inducible mechanisms enhance the resistance to clubroot disease.

  15. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    A Look of Hope Islam Mahmoud Sweity From 19 to 30 June 2017 CERN Meyrin, Main Building Islam Mahmoud Sweity Islam Mahmoud Sweity was born in 1997 at Beit Awwa, Palestine. She is currently following a course to get an Art diploma of Painting at the college of Fine Arts at An-Najah National University under the supervision of Esmat Al As'aad. Her portraits, landscapes and still life paintings are full of life and shining colours. Charged of emotional empathy they catch the attention of the viewer and are reminding us that life is beautiful and worth living in spite of all difficulties we have to go through. She participated in many exhibitions and has exposed her drawings in 2015 at CERN and in France in the framework of the exhibition "The Origin“, and in 2017 in the Former Yugoslav Republic of Macedonia, Palestina and Jordan. In this exhibition the oil paintings made in the past year will be presented. For more information : staff.association@cern.ch | T&eacu...

  16. Exhibition

    CERN Multimedia

    Staff Association

    2016-01-01

    Encounters Hanne Blitz From February 1st to 12th 2016 CERN Meyrin, Main Building What is our reaction to a first encounter with a tourist attraction? Contemporary Dutch painter Hanne Blitz captures visitors' responses to art and architecture, sweeping vistas and symbolic memorials. Encounters, a series of oil paintings curated specially for this CERN exhibition, depicts tourists visiting cultural highlights around the world. A thought-provoking journey not to be missed, and a tip of the hat to CERN's large Hadron Collider.

  17. Evaluation of soybean genotypes for resistance to charcoal rot

    Science.gov (United States)

    Charcoal rot caused by Macrophomina phaseolina causes more yield loss in soybean than most other diseases in the southern U.S.A. There are no commercial genotypes marketed as resistant to charcoal rot of soybean. Reactions of 27 maturity group (MG) III, 29 Early MG IV, 34 Late MG IV, and 59 MG V gen...

  18. Estimation of partial resistance in potato genotypes against Meloidogyne chitwoodi

    NARCIS (Netherlands)

    Norshie, P.M.; Been, T.H.; Schomaker, C.H.

    2011-01-01

    Three new potato genotypes, designated AR 04-4107, AR 04-4096 and AR 04-4098, with resistance towards Meloidogyne chitwoodi, and the susceptible cv. Désirée were grown at a range of population densities of M. chitwoodi in a climate-controlled glasshouse in order to establish the presence and degree

  19. Phenotypic and genotypic antimicrobial resistance of staphylococci from bovine milk.

    Science.gov (United States)

    Kot, B; Piechota, M; Wolska, K M; Frankowska, A; Zdunek, E; Binek, T; Kłopotowska, E; Antosiewicz, M

    2012-01-01

    The aim of this study was to examine phenotypic and genotypic antimicrobial resistance of staphylococci from milk samples from cows with subclinical and clinical mastitis and from cows without mastitis symptoms to methicillin, tetracyclines, macrolides and lincosamides (ML). Of 207 strains, including 34 S. aureus and 173 coagulase-negative staphylococci (CNS), 11 (6.4%) CNS strains were phenotypically resistant to methicillin. The mecA gene was detected by PCR only in two S. xylosus strains and one strain of S. epidermidis and S. simulans. No methicillin-resistant S. aureus strains were observed. In methicillin-resistant strains with mecA, gene resistance to other investigated antibiotics was not observed. Phenotypic resistance to tetracycline was detected in 11.0% of CNS strains and 47.4% of them carried the tetK gene. Of 173 CNS strains studied, 27 (15.6%) were resistant to at least one ML antibiotic. The resistance gene ermC was detected in 55.5% of the 27 ML-resistant strains. The ermA and ermB genes were detected in 14.8% and 11.1% of ML-resistant CNS strains, respectively. Antimicrobial resistance to methicillin, tetracyclines and macrolides was detected more frequently in staphylococcal strains from clinical mastitis compared to animals with subclinical symptoms and without mastitis, while the resistance to lincosamides showed a similar frequency in all groups of cows. In conclusion, CNS species from bovine milk differ in phenotypic and genotypic antimicrobial resistance profiles, and the use of PCR technique alone for the detection of methicillin, macrolide, lincosamide and tetyracycline resistance in CNS from cattle is not reliable.

  20. Exhibition

    CERN Multimedia

    Staff Association

    2017-01-01

    Sintropie Flavio Pellegrini From 13 to 24 March 2017 CERN Meyrin, Main Building Energia imprigionata - Flavio Pellegrini. The exhibition is composed by eleven wood artworks with the expression of movement as theme. The artworks are the result of harmonics math applied to sculpture. The powerful black colour is dominated by the light source, generating reflexes and modulations. The result is a continuous variation of perspective visions. The works generate, at a first approach, an emotion of mystery and incomprehension, only a deeper contemplation lets one discover entangling and mutative details, evidencing the elegance of the lines and letting the meaning emerge. For more information : staff.association@cern.ch | Tél: 022 766 37 38

  1. Longitudinal genotyping of Candida dubliniensis isolates reveals strain maintenance, microevolution, and the emergence of itraconazole resistance.

    LENUS (Irish Health Repository)

    Fleischhacker, M

    2010-05-01

    We investigated the population structure of 208 Candida dubliniensis isolates obtained from 29 patients (25 human immunodeficiency virus [HIV] positive and 4 HIV negative) as part of a longitudinal study. The isolates were identified as C. dubliniensis by arbitrarily primed PCR (AP-PCR) and then genotyped using the Cd25 probe specific for C. dubliniensis. The majority of the isolates (55 of 58) were unique to individual patients, and more than one genotype was recovered from 15 of 29 patients. A total of 21 HIV-positive patients were sampled on more than one occasion (2 to 36 times). Sequential isolates recovered from these patients were all closely related, as demonstrated by hybridization with Cd25 and genotyping by PCR. Six patients were colonized by the same genotype of C. dubliniensis on repeated sampling, while strains exhibiting altered genotypes were recovered from 15 of 21 patients. The majority of these isolates demonstrated minor genetic alterations, i.e., microevolution, while one patient acquired an unrelated strain. The C. dubliniensis strains could not be separated into genetically distinct groups based on patient viral load, CD4 cell count, or oropharyngeal candidosis. However, C. dubliniensis isolates obtained from HIV-positive patients were more closely related than those recovered from HIV-negative patients. Approximately 8% (16 of 194) of isolates exhibited itraconazole resistance. Cross-resistance to fluconazole was only observed in one of these patients. Two patients harboring itraconazole-resistant isolates had not received any previous azole therapy. In conclusion, longitudinal genotyping of C. dubliniensis isolates from HIV-infected patients reveals that isolates from the same patient are generally closely related and may undergo microevolution. In addition, isolates may acquire itraconazole resistance, even in the absence of prior azole therapy.

  2. An investigation of classification algorithms for predicting HIV drug resistance without genotype resistance testing

    CSIR Research Space (South Africa)

    Brandt, P

    2014-01-01

    Full Text Available is limited in low-resource settings. In this paper we investigate machine learning techniques for drug resistance prediction from routine treatment and laboratory data to help clinicians select patients for confirmatory genotype testing. The techniques...

  3. Genotypes and antibiotic resistance of canine Campylobacter jejuni isolates.

    Science.gov (United States)

    Amar, Chantal; Kittl, Sonja; Spreng, David; Thomann, Andreas; Korczak, Bożena M; Burnens, André P; Kuhnert, Peter

    2014-01-10

    Campylobacter jejuni is the most important cause of bacterial gastroenteritis in humans. It is a commensal in many wild and domestic animals, including dogs. Whereas genotypes of human and chicken C. jejuni isolates have been described in some detail, only little information on canine C. jejuni genotypes is available. To gain more information on genotypes of canine C. jejuni and their zoonotic potential, isolates from routine diagnostics of diarrheic dogs as well as isolates of a prevalence study in non-diarrheic dogs were analyzed. Prevalence of thermophilic Campylobacter among non-diarrheic dogs was 6.3% for C. jejuni, 5.9% for Campylobacter upsaliensis and 0.7% for Campylobacter coli. The C. jejuni isolates were genotyped by multi locus sequence typing (MLST) and flaB typing. Resistance to macrolides and quinolones was genetically determined in parallel. Within the 134 genotyped C. jejuni isolates 57 different sequence types (ST) were found. Five STs were previously unrecognized. The most common STs were ST-48 (11.2%), ST-45 (10.5%) and ST-21 (6.0%). Whereas no macrolide resistance was found, 28 isolates (20.9%) were resistant to quinolones. ST-45 was significantly more prevalent in diarrheic than in non-diarrheic dogs. Within the common time frame of isolation 94% of the canine isolates had a ST that was also found in human clinical isolates. In conclusion, prevalence of C. jejuni in Swiss dogs is low but there is a large genetic overlap between dog and human isolates. Given the close contact between human and dogs, the latter should not be ignored as a potential source of human campylobacteriosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Whitefly population dynamics and evaluation of whitefly-transmitted tomato yellow leaf curl virus (TYLCV)-resistant tomato genotypes as whitefly and TYLCV reservoirs.

    Science.gov (United States)

    Srinivasan, Rajagopalbabu; Riley, David; Diffie, Stan; Sparks, Alton; Adkins, Scott

    2012-08-01

    Sweetpotato whitefly, Bemisia tabaci (Gennadius), and whitefly-transmitted tomato yellow leaf curl virus (TYLCV) are major threats to tomato production in the southeastern United States. TYLCV was introduced to Florida from the Caribbean islands and has spread to other southern states of the United States. In Georgia, in recent years, the incidence of TYLCV has been steadily increasing. Studies were conducted to monitor population dynamics of whiteflies in the vegetable production belt of Georgia, to evaluate TYLCV-resistant genotypes against whiteflies and TYLCV, and to assess the potential role of resistant genotypes in TYLCV epidemiology. Monitoring studies indicated that the peak incidence of whiteflies varied seasonally from year to year. In general, whitefly populations were not uniformly distributed. Tomato genotypes exhibited minor differences in their ability to support whitefly populations. TYLCV symptoms were visually undetectable in all but one resistant genotype. The infection rates (visually) in susceptible genotypes ranged from 40 to 87%. Greenhouse inoculations with viruliferous whiteflies followed by polymerase chain reaction (PCR) indicated that up to 100% of plants of resistant genotypes were infected, although predominantly symptomless. TYLCV acquisition by whiteflies from TYLCV-infected genotypes was tested by PCR; TYLCV acquisition rates from resistant genotypes were less than from susceptible genotypes. Nevertheless, this difference did not influence TYLCV transmission rates from resistant to susceptible genotypes. Results emphasize that resistant genotypes can serve as TYLCV and whitefly reservoirs and potentially influence TYLCV epidemics.

  5. Molecular genotyping of herbicide resistance in P. minor: ACCase resistance.

    Science.gov (United States)

    Singh, Rajender; Sharma, Davinder; Raghav, Nishu; Chhokar, Rajender Singh; Sharma, Indu

    2015-02-01

    Little seed canary grass (Phalaris minor Retz.) populations resistant to herbicides that inhibit acetyl-CoA carboxylase (ACCase) represent an increasingly important weed control problem in northern India. The objective of this study was to develop DNA-based markers to differentiate herbicide-resistant and herbicide-susceptible population of P. minor. Primers were designed to amplify the conserved region carrying two reported mutations Trp2027 to Cys and Ile2041 to Asn conferring ACCase inhibitor resistance in several grass weeds and subjected to single-strand conformational polymorphism (SSCP) to detect the mutations. Five distinctive electrophoretic patterns on non-denaturing PAGE were observed, and four patterns were found to be associated with ACCase herbicide resistance in P. minor. The PCR-SSCP test developed in this study confirmed 17 resistant populations to contain mutations in CT domain of ACCase gene. This is the first report of rapid and easy molecular diagnosis of ACCase herbicide-resistant and herbicide-sensitive population of P. minor through PCR-SSCP analysis.

  6. HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing.

    Science.gov (United States)

    Rhee, Soo-Yon; Jordan, Michael R; Raizes, Elliot; Chua, Arlene; Parkin, Neil; Kantor, Rami; Van Zyl, Gert U; Mukui, Irene; Hosseinipour, Mina C; Frenkel, Lisa M; Ndembi, Nicaise; Hamers, Raph L; Rinke de Wit, Tobias F; Wallis, Carole L; Gupta, Ravindra K; Fokam, Joseph; Zeh, Clement; Schapiro, Jonathan M; Carmona, Sergio; Katzenstein, David; Tang, Michele; Aghokeng, Avelin F; De Oliveira, Tulio; Wensing, Annemarie M J; Gallant, Joel E; Wainberg, Mark A; Richman, Douglas D; Fitzgibbon, Joseph E; Schito, Marco; Bertagnolio, Silvia; Yang, Chunfu; Shafer, Robert W

    2015-01-01

    The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART) in the low- and middle-income countries (LMICs) hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR) and enable care-providers to determine which individuals with virological failure (VF) on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC) genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs). This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI)-associated DRMs (M184V and K65R) and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M) would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI)-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

  7. Hepatitis B virus genotypes and resistance mutations in patients under long term lamivudine therapy: characterization of genotype G in Brazil

    Directory of Open Access Journals (Sweden)

    Brandão Carlos E

    2008-01-01

    Full Text Available Abstract Background Lamivudine is an oral nucleoside analogue widely used for the treatment of chronic hepatitis B. The main limitation of lamivudine use is the selection of resistant mutations that increases with time of utilization. Hepatitis B virus (HBV isolates have been classified into eight genotypes (A to H with distinct geographical distributions. HBV genotypes may also influence pathogenic properties and therapeutic features. Here, we analyzed the HBV genotype distribution and the nature and frequency of lamivudine resistant mutations among 36 patients submitted to lamivudine treatment for 12 to 84 months. Results Half of the patients were homosexual men. Only 4/36 (11% patients were HBV DNA negative. As expected for a Brazilian group, genotypes A (24/32 positive individuals, 75%, D (3/32, 9.3% and F (1/32, 3% were present. One sample was from genotype C, which is a genotype rarely found in Brazil. Three samples were from genotype G, which had not been previously detected in Brazil. Lamivudine resistance mutations were identified in 20/32 (62% HBV DNA positive samples. Mean HBV loads of patients with and without lamivudine resistance mutations were not very different (2.7 × 107 and 6.9 × 107 copies/mL, respectively. Fifteen patients showed the L180M/M204V lamivudine resistant double mutation. The triple mutant rt173V/180M/204V, which acts as a vaccine escape mutant, was found in two individuals. The three isolates of genotype G were entirely sequenced. All three showed the double mutation L180M/M204V and displayed a large genetic divergence when compared with other full-length genotype G isolates. Conclusion A high (55% proportion of patients submitted to long term lamivudine therapy displayed resistant mutations, with elevated viral load. The potential of transmission of such HBV mutants should be monitored. The identification of genotypes C and G, rarely detected in South America, seems to indicate a genotype distribution different

  8. Corrosion resistant iron aluminides exhibiting improved mechanical properties and corrosion resistance

    Science.gov (United States)

    Liu, Chain T.; McKamey, Claudette G.; Tortorelli, Peter F.; David, Stan A.

    1994-01-01

    The specification discloses a corrosion-resistant intermetallic alloy comprising, in atomic percent, an FeAl iron aluminide containing from about 30 to about 40% aluminum alloyed with from about 0.01 to 0.4% zirconium and from 0.01 to about 0.8% boron. The alloy exhibits considerably improved room temperature ductility for enhanced usefulness in structural applications. The high temperature strength and fabricability is improved by alloying with molybdenum, carbon, chromium and vanadium.

  9. Activity of ceftobiprole against Streptococcus pneumoniae isolates exhibiting high-level resistance to ceftriaxone.

    Science.gov (United States)

    Davies, Todd A; Flamm, Robert K; Lynch, A Simon

    2012-06-01

    Tracking Resistance in the US Today (TRUST) 2008 surveillance data showed that 6% of Streptococcus pneumoniae were non-susceptible to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 2 μg/mL] and that 8% of the ceftriaxone-non-susceptible isolates exhibited high-level resistance (MIC ≥ 8 μg/mL). Here we describe the activity of ceftobiprole against ceftriaxone-resistant isolates and characterise the genotypic traits associated with resistance. Thirty isolates with ceftriaxone MICs ≥ 8 μg/mL were analysed by sequencing of penicillin-binding protein (PBP) and murM genes. Sequencing of pbp1a, pbp2b and pbp2x showed nine PBP patterns, with the most common (n=17) being: PBP1a T371S (STMK motif), P432T (SRNVP motif); PBP2b T446A (SSNT motif), A619G (KTGTA motif); and PBP2x T338A and M339F (STMK motif), L364F, I371T, R384G, M400T, L546V (LKSGT motif); six isolates had the same pattern without the PBP2b A619G change. For these 23 isolates, MICs were 8 μg/mL for ceftriaxone, 4-8 μg/mL for penicillin and 0.5-2 μg/mL for ceftobiprole. The remaining seven isolates with higher MICs (ceftriaxone 8-32 μg/mL, penicillin 4-32 μg/mL and ceftobiprole 2-4 μg/mL) had fewer PBP active-site motif substitutions. The majority of isolates (17/30) had murM alleles similar to the wild-type, whilst the rest had alleles reflecting a mosaic structure. No murM alleles were associated with higher MICs. Against these 30 isolates, ceftobiprole was 4-16-fold more active than ceftriaxone. Widely described PBP and MurM substitutions probably account for the high ceftriaxone MICs (8 μg/mL) in the majority of isolates. However, seven isolates with ceftriaxone MICs of 8-32 μg/mL had fewer PBP substitutions in active-site motifs, suggesting either that there is another resistance mechanism or that unique PBP mutations may contribute to high-level β-lactam resistance.

  10. Correlation between virulence genotype and fluoroquinolone resistance in carbapenem-resistant Pseudomonas aeruginosa.

    Science.gov (United States)

    Cho, Hye Hyun; Kwon, Kye Chul; Kim, Semi; Koo, Sun Hoe

    2014-07-01

    Pseudomonas aeruginosa is a clinically important pathogen that causes opportunistic infections and nosocomial outbreaks. Recently, the type III secretion system (TTSS) has been shown to play an important role in the virulence of P. aeruginosa. ExoU, in particular, has the greatest impact on disease severity. We examined the relationship among the TTSS effector genotype (exoS and exoU), fluoroquinolone resistance, and target site mutations in 66 carbapenem-resistant P. aeruginosa strains. Sixty-six carbapenem-resistant P. aeruginosa strains were collected from patients in a university hospital in Daejeon, Korea, from January 2008 to May 2012. Minimum inhibitory concentrations (MICs) of fluoroquinolones (ciprofloxacin and levofloxacin) were determined by using the agar dilution method. We used PCR and sequencing to determine the TTSS effector genotype and quinolone resistance-determining regions (QRDRs) of the respective target genes gyrA, gyrB, parC, and parE. A higher proportion of exoU+ strains were fluoroquinolone-resistant than exoS+ strains (93.2%, 41/44 vs. 45.0%, 9/20; P≤0.0001). Additionally, exoU+ strains were more likely to carry combined mutations than exoS+ strains (97.6%, 40/41 vs. 70%, 7/10; P=0.021), and MIC increased as the number of active mutations increased. The recent overuse of fluoroquinolone has led to both increased resistance and enhanced virulence of carbapenem-resistant P. aeruginosa. These data indicate a specific relationship among exoU genotype, fluoroquinolone resistance, and resistance-conferring mutations.

  11. HIV-1 Drug Resistance Mutations: Potential Applications for Point-of-Care Genotypic Resistance Testing.

    Directory of Open Access Journals (Sweden)

    Soo-Yon Rhee

    Full Text Available The increasing prevalence of acquired and transmitted HIV-1 drug resistance is an obstacle to successful antiretroviral therapy (ART in the low- and middle-income countries (LMICs hardest hit by the HIV-1 pandemic. Genotypic drug resistance testing could facilitate the choice of initial ART in areas with rising transmitted drug resistance (TDR and enable care-providers to determine which individuals with virological failure (VF on a first- or second-line ART regimen require a change in treatment. An inexpensive near point-of-care (POC genotypic resistance test would be useful in settings where the resources, capacity, and infrastructure to perform standard genotypic drug resistance testing are limited. Such a test would be particularly useful in conjunction with the POC HIV-1 viral load tests that are currently being introduced in LMICs. A POC genotypic resistance test is likely to involve the use of allele-specific point mutation assays for detecting drug-resistance mutations (DRMs. This study proposes that two major nucleoside reverse transcriptase inhibitor (NRTI-associated DRMs (M184V and K65R and four major NNRTI-associated DRMs (K103N, Y181C, G190A, and V106M would be the most useful for POC genotypic resistance testing in LMIC settings. One or more of these six DRMs was present in 61.2% of analyzed virus sequences from ART-naïve individuals with intermediate or high-level TDR and 98.8% of analyzed virus sequences from individuals on a first-line NRTI/NNRTI-containing regimen with intermediate or high-level acquired drug resistance. The detection of one or more of these DRMs in an ART-naïve individual or in a individual with VF on a first-line NRTI/NNRTI-containing regimen may be considered an indication for a protease inhibitor (PI-containing regimen or closer virological monitoring based on cost-effectiveness or country policy.

  12. Human endometrial side population cells exhibit genotypic, phenotypic and functional features of somatic stem cells.

    Directory of Open Access Journals (Sweden)

    Irene Cervelló

    Full Text Available During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC population. Here we explore the hypothesis that human endometrial side population (SP cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC.

  13. Transgenic mice overexpressing renin exhibit glucose intolerance and diet-genotype interactions

    Directory of Open Access Journals (Sweden)

    Sarah J. Fletcher

    2013-01-01

    Full Text Available Numerous animal and clinical investigations have pointed to a potential role of the renin-angiotensin system (RAS in the development of insulin resistance and diabetes in conditions of expanded fat mass. However, the mechanisms underlying this association remain unclear. We used a transgenic mouse model overexpressing renin in the liver (RenTgMK to examine the effects of chronic activation of RAS on adiposity and insulin sensitivity. Hepatic overexpression of renin resulted in constitutively elevated plasma angiotensin II (4-6-fold increase vs. wild type. Surprisingly, RenTgMK mice developed glucose intolerance despite low levels of adiposity and insulinemia. The transgenics also had lower plasma triglyceride levels. Glucose intolerance in transgenic mice fed a low-fat diet was comparable to that observed in high fat-fed wild type mice. Glucose intolerance was exacerbated by high-fat feeding, only in female transgenic mice. These studies demonstrate that overexpression of renin and associated hyperangiotensinemia impair glucose tolerance in a diet-dependent manner and further support a consistent role of RAS in the pathogenesis of diabetes and insulin resistance, independent of changes in fat mass.

  14. Identification of stable resistance to Phytophthora infestans in potato genotypes evaluated in field experiments in Peru

    DEFF Research Database (Denmark)

    Wulff, Ednar Gadelha; Pérez, W.; Nelson, R.J.;

    2007-01-01

    -parametric test. The potato genotypes were tested in seven experiments over two years in the vicinity of Comas, Peru, an area used by the International potato Center to screen for resistance to late blight. Results of the two analyses generally correlated and indicated that quantitative resistance to P. infestans......Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non...... yearly means of the relative area under the disease progress curve (rAUDPC), genotypes could be assigned to one of three resistance categories, resistant, moderately resistant or Susceptible, but the need for a more readily applicable and truly quantitative scale for resistance was noted. Based...

  15. Ergosterol concentration and variability in genotype-by-pathogen interaction for grain mold resistance in sorghum.

    Science.gov (United States)

    Mpofu, Leo T; McLaren, Neal W

    2014-08-01

    A lack of understanding of host-by-pathogen relations can hinder the success of breeding for resistance to a major disease. Fungal strain pathogenicity has to be understood from the virulence it can cause on susceptible genotypes and host resistance indicates which genotypes have resistance genes. Where the two worlds meet lies the place where researchers match the prevalent pathogen in the area of production with resistant varieties. This paper uses ergosterol concentration analysis as a measure of fungal biomass accumulation to assess levels of resistance in host genotypes. 11 sorghum genotypes were inoculated with 5 strains of fungi that are known to be associated with grain mold disease of sorghum. The resulting interaction was analyzed using GGE Biplot analysis and Cluster analysis which showed that none of the genotypes were resistant to Phoma sorghina and Curvularia lunata. Three genotypes were resistant to Fusarium thapsinum. One fungal strain (Alternaria alternata) does not contribute any significant damage in the grain mold disease. Fusarium graminearum causes very little grain mold disease. There was no correlation between the fungal strains. Visual scoring did not correlate with ergosterol accumulation. Resistance to grain mold in sorghum is shown to be due to vertical or specific resistance genes. Sorghum breeders should, therefore, identify predominant fungal strains in their localities and then locate and tag these resistance genes in their germplasm and pyramid them in commercial varieties.

  16. [Evaluation of penicillin-binding protein genotypes in penicillin susceptible and resistant Streptococcus pneumoniae isolates].

    Science.gov (United States)

    Aslan, Gönül; Tezcan, Seda; Delialioğlu, Nuran; Aydın, Fatma Esin; Kuyucu, Necdet; Emekdaş, Gürol

    2012-04-01

    Penicillin-binding proteins (PBPs) are the natural targets of beta-lactam antibiotics and mutations in pbp1a, pbp2b, and pbp2x genes, which encode PBPs, are responsible for resistance to beta-lactams in Streptococcus pneumoniae. In the present study, we intended to determine how often the common mutation patterns occurred within the pbp1a, pbp2b, and pbp2x PBP gene regions and evaluate the PBP genotype mutations which were associated with penicillin resistance in several penicillin-susceptible and - resistant S.pneumoniae isolates in Mersin, Turkey. A total of 62 S.pneumoniae strains isolated from different clinical specimens (32 nasopharyngeal swab, 16 sputum, 3 blood, 3 wound, 2 cerebrospinal fluids and one of each urine, abscess, bronchoalveolar lavage, conjunctival swab, tracheal aspirate, middle ear effusion) were included in the study. Penicillin susceptibilities of the isolates were searched by disc diffusion and E-test methods, and 23 of them were identified as susceptible, 31 were intermediate susceptible, and eight were resistant to penicillin. A rapid DNA extraction procedure was performed for the isolation of nucleic acids from the strains. Distribution of PBP gene mutations in pbp1a, pbp2b, and pbp2x gene regions related to penicillin resistance was determined by using a wild-type specific polymerase chain reaction (PCR) based technique. PBP gene alterations of those isolates were also evaluated in relation to penicillin susceptibility and resistance patterns. Twenty two (95.7%) of 23 penicillin-susceptible S.pneumoniae isolates exhibited no mutation in the three PBP genes (pbp1a, pbp2x, and pbp 2b), while 1 (4.3%) of these harbored mutations in all of the three PBP genes. The penicillin-intermediate susceptible S.pneumoniae isolates exhibited various combinations of mutations. One (3.2%) of 31 penicillin-intermediate susceptible isolates exhibited no mutation in the three PBP genes, while 22 (71%) of them yielded mutations in all of the three PBP

  17. Preliminary results on evaluation of chickpea, Cicer arietinum, genotypes for resistance to the pulse beetle, Callosobruchus maculatus.

    Science.gov (United States)

    Erle, F; Ceylan, F; Erdemir, T; Toker, C

    2009-01-01

    Abstract The chickpea, Cicer arietinum L. (Fabales: Fabaceae), seeds are vulnerable, both in the field and in storage, to attack by seed-beetles. Beetles of the genus Callosobruchus are major storage pests of chickpea crops and cause considerable economic losses. In the present study, a total of 11 chickpea genotypes including five 'kabuli' (Mexican white, Diyar, CA 2969, ILC 8617 and ACC 245) and six 'desi' chickpeas (ICC 1069, ICC 12422, ICC 14336, ICC 4957, ICC 4969 and ICC 7509) were evaluated for resistance to the pulse beetle Callosobruchus maculatus F. (Coleoptera: Bruchidae). Resistance was evaluated by measuring percent damage to seeds. Damage to seeds by C. maculatus was manifested by the round exit holes with the 'flap' of seed coat made by emerging adults. Of the 11 genotypes tested, only one (ICC 4969) exhibited a complete resistance to C. maculatus in both free-choice and no-choice tests; no seed damage was found over the test period. In general, the 'desi' chickpeas were more resistant to C. maculatus than the 'kabuli' chickpeas. Among the tested chickpea genotypes, only ICC 4969 can be used as a source of C. maculatus resistance in breeding programmes that could then be grown in organic cultivation free from pesticides.

  18. Assessment of the photosynthesis-related traits and high temperature resistance in tetraploid wheat (Triticum L. genotypes

    Directory of Open Access Journals (Sweden)

    Katarina OLSOVSKA

    2013-06-01

    Full Text Available The collection of 10 parental lines of tetraploid wheat genotypes with various origin was cultivated in growth chamber. Leaf and growth traits such as assimilation pigments content, dry mass and leaf area of plants were measured. The genotype differences were recognized by chlorophyll a fluorescence fast kinetics method applied on penultimate young wheat leaves. Consequently, heat stress susceptibility based on the exposure of whole plants in pots to air temperature of 42oC for 6 hours was measured, too. Rapid chlorophyll a fluorescence kinetics method gave us better knowledge about differences among tetraploid wheat genotypes collection comparing to classic assimilation pigments analyse. Genotypes with higher content of pigments did not always exhibit good resistance against heat stress. Using the chlorophyll fluorescence parameters, the rating of genotypes based on photosynthetic performance as well as photosystem II (PSII thermostability was done. We identified the genotypes TRG7 (Triticum turgidum subsp. turgidum, PI 384230, Ethiopia and RONCAL (Triticum turgidum subsp. dicoccon, TRI 17700, Spain as the perspective donors of genes for better thermostability of photosynthetic apparatus in changed climate conditions and material into wheat efficiency breeding programs.

  19. Beijing genotype of Mycobacterium tuberculosis is significantly associated with high-level fluoroquinolone resistance in Vietnam.

    Science.gov (United States)

    Duong, Duy An; Nguyen, Thi Hong Duyen; Nguyen, Thi Ngoc Lan; Dai, Viet Hoa; Dang, Thi Minh Ha; Vo, Sy Kiet; Do, Dang Anh Thu; Nguyen, Van Vinh Chau; Nguyen, Huy Dung; Dinh, Ngoc Sy; Farrar, Jeremy; Caws, Maxine

    2009-11-01

    Consecutive fluoroquinolone (FQ)-resistant isolates (n = 109) identified at the Pham Ngoc Thach Hospital for Tuberculosis, Ho Chi Minh City, Vietnam, were sequenced in the quinolone resistance-determining regions of the gyrA and gyrB genes and typed by large sequence polymorphism typing and spoligotyping to identify the Beijing genotype of Mycobacterium tuberculosis. Beijing genotype prevalence was compared with 109 consecutive isolates from newly presenting patients with pulmonary tuberculosis from the hospital outpatient department. Overall, 82.6% (n = 90/109) of isolates had mutations in gyrAB. Nine novel mutations were identified in gyrB (S486F, N538T, T539P, D500A, D500H, D500N, G509A, E540V, and E540D). The influence of these novel gyrB mutations on FQ resistance is not proven. The Beijing genotype was significantly associated with FQ resistance (odds ratio [OR], 2.39 [95% confidence interval {CI}, 1.34 to 4.25]; P = 0.003). Furthermore, Beijing genotype FQ-resistant isolates were significantly more likely than FQ-resistant isolates of other genotypes to have gyrA mutations (OR, 7.75 [95% CI, 2.84 to 21.15]; P = 0.0001) and high-level (>8 microg/ml) FQ resistance (OR, 11.0 [95% CI, 2.6 to 47.0]; P = 0.001). The underlying mechanism of the association of the Beijing genotype with high-level FQ resistance in this setting remains to be determined. The association of the Beijing genotype with relatively high-level FQ resistance conferred by specific gyrA mutations reported here is of grave concern given the epidemic spread of the Beijing genotype and the current hopes for shorter first-line treatment regimens based on FQs.

  20. Effects of insecticides on strawberry aphid Chaetosiphon fragaefolii (Cockerell) on resistant and susceptible strawberry genotypes

    OpenAIRE

    2011-01-01

    Strawberry aphid, Chaetosiphon fragaefolii (Cockerell), is the most important vector of strawberry virus. Breeding of genotypes resistant to this pest is an important preventive control measure, which can be compatible with rational insecticide application. The aim of the paper was to determine effects of dimethoate and deltamethrin on C. fragaefolii populations reared on two strawberry genotypes different in susceptibility: susceptible strawberry cultivar ...

  1. Identification of stable resistance to Phytophthora infestans in potato genotypes evaluated in field experiments in Peru

    DEFF Research Database (Denmark)

    Wulff, Ednar Gadelha; Pérez, W.; Nelson, R.J.;

    2007-01-01

    Abstract: In this study, genotype by environment (G x E) interactions and phenotypic stability of resistance to Phytophthora infestans, the cause of late blight, were analysed in Peru lot 13 potato genotypes, using additive main effects and multiplicative interaction (AMMI) analysis and Huehn's non...

  2. Analysis of genetic homology and genotyping in Carbapenems-resistant Klebsiella pneumonia

    Institute of Scientific and Technical Information of China (English)

    杨丽君

    2013-01-01

    Objective To investigate genotyping and homology of Carbapenems-resistant Klebsiella pneumonia isolated from clinical specimens.Methods A total of 175 clinical isolates of Carbapenemsresistant Klebsiella pneumoniae were isolated from clinical specimens from January 2011 to June 2012

  3. Defining multidrug-resistant tuberculosis: correlating GenoType MTBDRplus assay results with minimum inhibitory concentrations.

    Science.gov (United States)

    Kambli, Priti; Ajbani, Kanchan; Sadani, Meeta; Nikam, Chaitali; Shetty, Anjali; Udwadia, Zarir; Georghiou, Sophia B; Rodwell, Timothy C; Catanzaro, Antonino; Rodrigues, Camilla

    2015-05-01

    This study correlates MICs of rifampicin (RIF) and isoniazid (INH) with GenoType MTBDRplus assay results for drug-resistant Mycobacterium tuberculosis (MTB) clinical isolates. MICs of RIF and INH were established for 84 and 90 isolates, respectively, testing 7 concentrations of each drug. Genotypic resistance to each drug was determined by GenoType MTBDRplus assay with 50 representative mutations confirmed by pyrosequencing, with mutations in the rpoB gene associated with RIF resistance and mutations in the katG and/or inhA genes associated with INH resistance. Based upon the correlation of MICs with specific genetic profiles, relative resistance levels were established for each isolate. Results indicate that MTB phenotypic resistance, currently based upon the testing of isolate susceptibility to a single drug concentration, may be more accurately profiled via quantitative MICs, and therefore, the correlation of molecular diagnostic results with specific MICs may allow for more optimal treatment of infections.

  4. In Vitro screening of tomato genotypes for drought resistance using ...

    African Journals Online (AJOL)

    ... crop and area under production is limited by irrigation water scarcity. ... conditions indicating there ability to fight with sever water stress situation. ... and hybrids performed better than cultivated genotypes under all levels of water stress.

  5. Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Scott, N. L.; Sordillo, L. M.

    1994-01-01

    This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare......; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils...

  6. Identification of Resistance Gene to PVY and Its Relation to Marketable Tuber Yield of PVY Resistant Potato Genotypes

    Directory of Open Access Journals (Sweden)

    Hassan Hassanabadi

    2016-10-01

    Full Text Available In this study, the Rysto gene, originaly found in wild potato (Solanum stoloniferum, confers extreme resistance against PVY. It was identified in 21 potato clones and varieties and they were evaluated for some agronomic traits. For this purpose five trials were conducted. In first trial 320 potato genotypes were planted on the farm and 55 symptomless clone and cultivars were selected. In second trial, 55 genotypes along with sensitive control genotype (Desireh were planted in 20 cm pots in the greenhouse at 15-20 °C with three replications. After five weeks, upper leaves were infected artificially with sap from tobacco fresh leaves checked for infection with PVYNTN and additional infections were repeated after 48 hours. Symptoms were recorded and all plants were tested by enzyme-linked immunosorbent assay (ELISA about 4 weeks after inoculation. Plants that showed visual symptoms or/and gave at least a positive ELISA result were considered as susceptible and symptomless response with negative ELISA results were considered as resistant. In third trial, 23 genotypes were planted in the greenhouse and the PVY infected young tobacco shoots were grafted to symptomless genotypes with negative ELISA results with three replications and were selected as resistance genotypes. In fourth trial, all the PVY resistant genotypes were checked by molecular marker (STM0003 for detection of Rysto gene. Finally four potato varieties (Jelly, Sante, White Lady and Savalan cultivars and 19 advanced clones were regarded as carriers of Rysto gene. In the fifth experiment genotypes were evaluated for marketable tuber yield of varieties and clones resistant to virus PVY in field conditions and 397009-8 clone was selected as high-yielding and tolerant genotype to PVY virus. Also, This clone did also have appropriate quality traits like oval-round tuber shape, uniform tubers, short stolon length, light yellow flesh color, yellow skin color, good tuber dry matter percent

  7. Ability of Staphylococcus aureus coagulase genotypes to resist neutrophil bactericidal activity and phagocytosis

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller; Scott, N. L.; Sordillo, L. M.

    1994-01-01

    genotype. The interaction between bacteria and neutrophils was measured by phagocytosis and bactericidal effect. The average percent killing of bacteria was lowest (40.0%) with strains belonging to the most common genotype, medium (50%) with strains belonging to the intermediate type, and highest (64......; rare type, 10.5/cell). These findings suggest that one of the reasons for the variation in prevalence of different genotypes of S. aureus in the mammary gland is due to the superior ability of some types to resist phagocytosis and/or killing by bovine neutrophils......This study investigated the functional capabilities of neutrophils against different Staphylococcus aureus genotypes isolated from cows with mastitis. Six strains of S. aureus were chosen for use in the study, two with a common genotype, two with an intermediate genotype, and two with a rare...

  8. Phenotypic characterization of papaya genotypes to determine powdery mildew resistance

    Directory of Open Access Journals (Sweden)

    Marcelo Vivas

    2017-06-01

    Full Text Available In support of breeding of papaya (Carica papaya, the disease incidence and severity of powdery mildew (Ovulariopsis caricicola were evaluated in papaya genotypes. Two experiments in complete randomized blocks were carried out, one in the field and the other in a greenhouse. In field experiments, the lowest mean disease incidence was observed on the genotypes ‘Costa Rica’ and ‘Baixinho Super’, and the lowest mean disease severity on ‘Caliman M5’, ‘GTF’, ‘SH 11-08’, and ‘JS 11’. In the greenhouse experiment, the genotypes ‘Caliman M5’, ‘Golden’, ‘Kapoho Solo’, ‘Waimanalo’, ‘Mamão Bené’, ‘SH 12-07’, ‘JS 12’, and ‘GTF’ had the lowest mean incidence in at least one evaluation. On the other hand, for severity, the genotypes ‘Diva’, ‘Sunrise Solo 72/12’, ‘Kapoho Solo PA’, ‘Waimanalo’, ‘Maradol’, ‘Maradol GL’, ‘SH 15-04’, ‘FMV, ‘JS 12-4’, ‘SH 12-07’ and ‘Sekati FLM’ had the lowest means. These results indicate these genotypes for a possible use in breeding for reduction of powdery mildew intensity

  9. Genotypic variation for maize weevil resistance in eastern and ...

    African Journals Online (AJOL)

    ACSS

    ... Resources Research Institute, National Agricultural Research Organization, ... resistance and grain yield, suggesting that breeding for maize weevil resistance can be achieved without compromising grain yield. Key words: Sitophilus zeamais, weevil resistance, Zea mays ..... might be manifested as a result of changes.

  10. Transmission of extensively drug-resistant and multidrug resistant Mycobacterium tuberculosis in families identified by genotyping

    Institute of Scientific and Technical Information of China (English)

    YAN Li-ping; QIN Lian-hua; ZHANG Qing; SUN Hua; HAN Min; XIAO He-ping

    2013-01-01

    Background Diagnosis and appropriate treatment of multidrug-resistant tuberculosis (MDR-TB) remain major challenges.We sought to elucidate that persons who share a household with drug resistance tuberculosis patients are at high risk for primary drug resistance tuberculosis and how to prevent these outbreaks.Methods We used 12-locus mycobacterial interspersed repetitive unit and 7-locus variable-number tandem repeat to identify household transmission of extensively drug resistant and multiple drug resistant Mycobacterium tuberculosis in three families admitted in Shanghai Pulmonary Hospital affiliated with Tongji University.Drug susceptibility tests were done by the modified proportion method in the MGIT 960 system in the same time.Clinical data were also obtained from the subjects' medical records.Results All of the six strains were defined as Beijing genotype by the deletion-targeted multiplex PCR (DTM-PCR) identification on the genomic deletion RD105.Strains from family-1 had the same minisatellite interspersed repetitive unit (MIRU) pattem (232225172531) and the same MIRU pattern (3677235).Strains from family-2 had the same MIRU pattern (2212261553323) and the same MIRU pattern (3685134).Strains from family-3 did not have the same MIRU pattern and they differed at only one locus (223326173533,223325173533),and did not have the same VNTR pattern with two locus differed (3667233,3677234).Conclusions Household transmission exists in the three families.A clear chain of tuberculosis transmission within family exists.Tuberculosis susceptibility should be considered when there is more than one tuberculosis patients in a family.Household tuberculosis transmission could be prevented with adequate treatment of source patients.

  11. Genotypic variation in tolerance and resistance to fouling in the brown alga Fucus vesiculosus.

    Science.gov (United States)

    Honkanen, Tuija; Jormalainen, Veijo

    2005-06-01

    In this study, we examined genetic variation in resistance and tolerance to fouling organisms in the brown alga Fucus vesiculosus. We first grew 30 algal genotypes in the field, where we allowed fouling organisms to colonise the genotypes at natural levels. We then conducted a manipulative experiment, where we grew 20 genotypes of algae in aquaria with or without fouling organisms. We measured host resistance as the load of fouling organisms and tolerance as the slope of the regression of algal performance on fouling level. Fouling organisms decreased host growth and contents of phlorotannins and thus have the potential to act as selective agents on algal defenses. We found significant among-genotype variation in both resistance and tolerance to fouling. We did not find a trade-off between resistance and tolerance. We found a marginally significant cost of resistance, but no cost of tolerance. Our results thus indicate that both the tolerance and resistance of F. vesiculosus can evolve as a response to fouling and that the costs of resistance may maintain genetic variation in resistance.

  12. Drug-resistant tuberculosis in Central Mozambique: the role of a rapid genotypic susceptibility testing.

    Science.gov (United States)

    Namburete, Evangelina Inácio; Tivane, Inês; Lisboa, Miguelhete; Passeri, Margarida; Pocente, Renata; Ferro, Josefo Joao; Harrison, Lee H; Bollela, Valdes Roberto

    2016-08-17

    Genotypic molecular testing may be very helpful for tuberculosis (TB) drug-resistance surveillance and for treatment guidance in low resource settings. Descriptive analysis of M. tuberculosis isolates from Beira Central Hospital, Mozambique, during 2014-2015. Genotype MTBDRplus and MTBDRsl were used and patient medical records reviewed. To explore genotypic susceptibility profile of Mycobacterium tuberculosis, to first and second line drugs (SLD) in Beira Mozambique. Of 155 isolates, 16.1 % (25) were multidrug resistant (MDR), 8.4 % (13) isoniazid-monoresistant and 1.3 % (2) rifampicin-monoresistant. Among MDR-TB, 22.2 % showed primary and 77.8 % represented acquired resistance. The majority of patients with drug resistance had a history of previous TB treatment. Among 125 isolates tested for ethambutol and SLD, 7.2 % (9) were resistant to ethambutol, 4.8 % (6) to fluoroquinolones and 0.8 % (1) to ethambutol and fluoroquinolones. Resistance to injectable SLD was not detected. As far as we know this is the first report of a genotypic testing used to provide information about SLD resistance in Mozambique, where phenotypic susceptibility testing is usually unavailable. Extensively drug resistant TB was not detected in this isolates from Beira Mozambique.

  13. Complete genome sequence of Campylobacter jejuni RM1246-ERRC that exhibits resistance to Quaternary Ammonium Compounds

    Science.gov (United States)

    Campylobacter jejuni strain RM1246-ERRC is a clinical isolate. In laboratory experiments RM1246-ERRC exhibited resistance to the antimicrobial effects of quaternary ammonium compounds (QACs) when compared to other C. jejuni strains. The chromosome of RM1246-ERRC was determined to be 1,659,694 bp w...

  14. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    Science.gov (United States)

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  15. FECAL SOURCE TRACKING BY ANTIBIOTIC RESISTANCE ANALYSIS ON A WATERSHED EXHIBITING LOW RESISTANCE

    Science.gov (United States)

    The ongoing development of microbial source tracking has made it possible to identify contamination sources with varying accuracy, depending on the method used. The purpose of this study was done to test the efficiency of the antibiotic resistance analysis (ARA) method under low ...

  16. Predicting Bevirimat resistance of HIV-1 from genotype

    Directory of Open Access Journals (Sweden)

    Hoffmann Daniel

    2010-01-01

    Full Text Available Abstract Background Maturation inhibitors are a new class of antiretroviral drugs. Bevirimat (BVM was the first substance in this class of inhibitors entering clinical trials. While the inhibitory function of BVM is well established, the molecular mechanisms of action and resistance are not well understood. It is known that mutations in the regions CS p24/p2 and p2 can cause phenotypic resistance to BVM. We have investigated a set of p24/p2 sequences of HIV-1 of known phenotypic resistance to BVM to test whether BVM resistance can be predicted from sequence, and to identify possible molecular mechanisms of BVM resistance in HIV-1. Results We used artificial neural networks and random forests with different descriptors for the prediction of BVM resistance. Random forests with hydrophobicity as descriptor performed best and classified the sequences with an area under the Receiver Operating Characteristics (ROC curve of 0.93 ± 0.001. For the collected data we find that p2 sequence positions 369 to 376 have the highest impact on resistance, with positions 370 and 372 being particularly important. These findings are in partial agreement with other recent studies. Apart from the complex machine learning models we derived a number of simple rules that predict BVM resistance from sequence with surprising accuracy. According to computational predictions based on the data set used, cleavage sites are usually not shifted by resistance mutations. However, we found that resistance mutations could shorten and weaken the α-helix in p2, which hints at a possible resistance mechanism. Conclusions We found that BVM resistance of HIV-1 can be predicted well from the sequence of the p2 peptide, which may prove useful for personalized therapy if maturation inhibitors reach clinical practice. Results of secondary structure analysis are compatible with a possible route to BVM resistance in which mutations weaken a six-helix bundle discovered in recent experiments

  17. Genotype and Phenotype Patterns of Human Immunodeficiency Virus Type 1 Resistance to Enfuvirtide during Long-Term Treatment

    Science.gov (United States)

    Menzo, Stefano; Castagna, Antonella; Monachetti, Alessia; Hasson, Hamid; Danise, Anna; Carini, Elisabetta; Bagnarelli, Patrizia; Lazzarin, Adriano; Clementi, Massimo

    2004-01-01

    The human immunodeficiency virus type 1 (HIV-1) fusion inhibitor enfuvirtide has recently been introduced into clinical practice and has exhibited efficient anti-HIV-1 activity in combination with other antiretroviral agents. In the present study, we addressed the effect of long-term treatment with enfuvirtide on the intrahost evolution of HIV-1. The genotype and phenotype patterns and the relative replication capacity (rRC) of enfuvirtide-resistant HIV-1 mutants were evaluated in samples from 11 subjects (7 virological nonresponders and 4 responders) who received the compound for more than 1 year in combination with different regimens. Selection of one or more mutations clustering in a sequence (amino acids 36 to 45) of the gp41 N-terminal heptad repeat was observed in samples from the seven virological nonresponders but not in those from responders. In two subjects who discontinued enfuvirtide, reversion of the resistant genotype was detected within 3 months. Recombinant clones bearing mutated gp41 sequences displayed reduced susceptibilities to enfuvirtide, with the 50% inhibitory concentrations (IC50s) ranging from 0.6 to 12.8 μg/ml, whereas the IC50 for isolates with baseline sequences was 0.013 ± 0.010 μg/ml. Interestingly, long-term monitoring of resistant variants provided evidence that ongoing adaptation to the drug is paralleled by phenotypic changes. A limited drop in the rRC in the absence of drug was observed for clones from four of the seven nonresponders bearing mutations associated with resistance. Overall, the data indicate that the different genotype patterns associated with a detectable degree of HIV-1 resistance to enfuvirtide generated during long-term treatments are characterized by a substantially low genetic barrier, possible ongoing adaptation with increased degrees of resistance, and limited influence on the viral rRC. PMID:15328081

  18. Lettuce genotype resistance to "soft rot" caused by Pectobacterium carotovorum subsp. carotovorum

    Directory of Open Access Journals (Sweden)

    Kátia Cilene da Silva Felix

    2014-08-01

    Full Text Available Soft rot, caused by Pectobacterium carotovorum subsp. carotovorum (Pcc, is the main bacterial disease affecting lettuce (Lactuca sativa L. crops in Brazil and leads to significant yield losses. This study aimed to assess the reaction of lettuce genotypes to soft rot induced by a virulent isolate and the stability of the resistance to three isolates varying in virulence. Using a descriptive ordinal scale ranging from 1 to 9 a classification system was defined: class 1 = resistant (R: severity (Sev 3.5. Of the 41 tested genotypes, 14 were classified as MR and 27 as S when inoculated with a Pcc isolate of intermediate virulence. Eleven of these genotypes (four S and seven MR were selected to test their resistance stability against three other isolates with an increasing degree of virulence (Pcc36 < Pcc-A1.1 < Pcc-23. Out of the 11 genotypes eight retained the original classification and three moved from S to MR resistant class when challenged with the least virulent isolate. Vitória de Santo Antão was the only genotype classified as MR for all tested isolates and is a promising candidate for durable soft rot resistance breeding.

  19. Early detection of resistance to Mycosphaerella fijiensis in local genotypes of Musa in Ecuador

    OpenAIRE

    García, Galo Cedeño; Capello, Carmen Suarez; Coello, Danilo Vera; Fadda, Carlo; Jarvis, Devra; De Santis, Paola

    2017-01-01

    The aim of this research was to determine resistance reaction of 14 Musa genotypes against Mycosphaerella fijensis, causal agent of Black Sigatoka disease. Two experiments were conducted in laboratory and shadehause at Pichilingue research Station from the National Institute of Agricultural Research (INIAP), Ecuador. Genotypes considered were: Orito (AA), Guineo de jardín, Williams, Filipino, Gross Mitchel, Mulato and Morado, (AAA); Limeño, Maqueño, Dominico, Dominico-Hartón, Dominico gigante...

  20. Phenotypic and genotypic analysis of anti-tuberculosis drug resistance in Mycobacterium tuberculosis isolates in Myanmar.

    Science.gov (United States)

    Aung, Wah Wah; Ei, Phyu Win; Nyunt, Wint Wint; Swe, Thyn Lei; Lwin, Thandar; Htwe, Mi Mi; Kim, Kyung Jun; Lee, Jong Seok; Kim, Chang Ki; Cho, Sang Nae; Song, Sun Dae; Chang, Chulhun L

    2015-09-01

    Tuberculosis (TB) is one of the most serious health problems in Myanmar. Because TB drug resistance is associated with genetic mutation(s) relevant to responses to each drug, genotypic methods for detecting these mutations have been proposed to overcome the limitations of classic phenotypic drug susceptibility testing (DST). We explored the current estimates of drug-resistant TB and evaluated the usefulness of genotypic DST in Myanmar. We determined the drug susceptibility of Mycobacterium tuberculosis isolated from sputum smear-positive patients with newly diagnosed pulmonary TB at two main TB centers in Myanmar during 2013 by using conventional phenotypic DST and the GenoType MTBDRplus assay (Hain Lifescience, Germany). Discrepant results were confirmed by sequencing the genes relevant to each type of resistance (rpoB for rifampicin; katG and inhA for isoniazid). Of 191 isolates, phenotypic DST showed that 27.7% (n=53) were resistant to at least one first-line drug and 20.9% (n=40) were resistant to two or more, including 18.3% (n=35) multidrug-resistant TB (MDR-TB) strains. Monoresistant strains accounted for 6.8% (n=13) of the samples. Genotypic assay of 189 isolates showed 17.5% (n=33) MDR-TB and 5.3% (n=10) isoniazid-monoresistant strains. Genotypic susceptibility results were 99.5% (n=188) concordant and agreed almost perfectly with phenotypic DST (kappa=0.99; 95% confidence interval 0.96-1.01). The results highlight the burden of TB drug resistance and prove the usefulness of the genotypic DST in Myanmar.

  1. Differences in Aluminium Accumulation and Resistance between Genotypes of the Genus Fagopyrum

    Directory of Open Access Journals (Sweden)

    Benjamin Klug

    2015-08-01

    Full Text Available Aluminium (Al toxicity is a major factor reducing crop productivity worldwide. There is a broad variation in intra- and inter-specific Al resistance. Whereas the Al resistance mechanisms have generally been well explored in Al-excluding plant species, Al resistance through Al accumulation and Al tolerance is not yet well understood. Therefore, a set of 94 genotypes from three Fagopyrum species with special emphasis on F. esculentum Moench were screened, with the objective of identifying genotypes with greatly differing Al accumulation capacity. The genotypes were grown in Al-enriched peat-based substrate for 21 days. Based on the Al concentration of the xylem sap, which varied by a factor of five, only quantitative but not qualitative genotypic differences in Al accumulation could be identified. Aluminium and citrate and Al and Fe concentrations in the xylem sap were positively correlated suggesting that Fe and Al are loaded into and transported in the xylem through related mechanisms. In a nutrient solution experiment using six selected F. esculentum genotypes differing in Al and citrate concentrations in the xylem sap the significant correlation between Al and iron transport in the xylem could be confirmed. Inhibition of root elongation by Al was highly significantly correlated with root oxalate-exudation and leaf Al accumulation. This suggests that Al-activated oxalate exudation and rapid transport of Al to the shoot are prerequisites for the protection of the root apoplast from Al injury and thus overall Al resistance and Al accumulation in buckwheat.

  2. Differential expression of jasmonate biosynthesis genes in cacao genotypes contrasting for resistance against Moniliophthora perniciosa.

    Science.gov (United States)

    Litholdo, Celso G; Leal, Gildemberg A; Albuquerque, Paulo S B; Figueira, Antonio

    2015-10-01

    The resistance mechanism of cacao against M. perniciosa is likely to be mediated by JA/ET-signaling pathways due to the preferential TcAOS and TcSAM induction in a resistant genotype. The basidiomycete Moniliophthora perniciosa causes a serious disease in cacao (Theobroma cacao L.), and the use of resistant varieties is the only sustainable long-term solution. Cacao resistance against M. perniciosa is characterized by pathogen growth inhibition with reduced colonization and an attenuation of disease symptoms, suggesting a regulation by jasmonate (JA)/ethylene (ET) signaling pathways. The hypothesis that genes involved in JA biosynthesis would be active in the interaction of T. cacao and M. perniciosa was tested here. The cacao JA-related genes were evaluated for their relative quantitative expression in susceptible and resistant genotypes upon the exogenous application of ET, methyl-jasmonate (MJ), and salicylic acid (SA), or after M. perniciosa inoculation. MJ treatment triggered changes in the expression of genes involved in JA biosynthesis, indicating that the mechanism of positive regulation by exogenous MJ application occurs in cacao. However, a higher induction of these genes was observed in the susceptible genotype. Further, a contrast in JA-related transcriptional expression was detected between susceptible and resistant plants under M. perniciosa infection, with the induction of the allene oxide synthase gene (TcAOS), which encodes a key enzyme in the JA biosynthesis pathway in the resistant genotype. Altogether, this work provides additional evidences that the JA-dependent signaling pathway is modulating the defense response against M. perniciosa in a cacao-resistant genotype.

  3. Genotypic variability and phenotypic plasticity of cavitation resistance in Fagus sylvatica L. across Europe.

    Science.gov (United States)

    Wortemann, Rémi; Herbette, Stéphane; Barigah, Têtè Sévérien; Fumanal, Boris; Alia, Ricardo; Ducousso, Alexis; Gomory, Dusan; Roeckel-Drevet, Patricia; Cochard, Hervé

    2011-11-01

    Xylem cavitation resistance is a key physiological trait correlated with species tolerance to extreme drought stresses. Little is known about the genetic variability and phenotypic plasticity of this trait in natural tree populations. Here we measured the cavitation resistance of 17 Fagus sylvatica populations representative of the full range of the species in Europe. The trees were grown in three field trials under contrasting climatic conditions. Our findings suggest that the genotypic variability of cavitation resistance is high between genotypes of a given population. By contrast, no significant differences were found for this trait across populations, the mean population cavitation resistance being remarkably constant in each trial. We found a significant site effect and a significant site × population interaction, suggesting that cavitation resistance has a high phenotypic plasticity and that this plasticity is under genetic control. The implications of our findings for beech forest management in a context of climate change are discussed.

  4. multiple disease resistance in snap bean genotypes in kenya

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    bimodal pattern of rainfall with an annual mean of 1000 mm. .... the parent lines had intermediate resistance (Table. 6). Variety Star 2053 was ..... the parental varieties used as checks in the current study did ..... Authority), 2009. Export statistics ...

  5. Detection of Helicobacter pylori and the genotypes of resistance to clarithromycin and the heterogeneous genotype to this antibiotic in biopsies obtained from symptomatic children.

    Science.gov (United States)

    Aguilera-Correa, John Jairo; Urruzuno, Pedro; Barrio, Josefa; Martinez, María José; Agudo, Sonia; Somodevilla, Angela; Llorca, Laura; Alarcón, Teresa

    2017-02-01

    The aim of this study was to use a commercially available kit (GenoType® HelicoDR; Hain Life Science, Germany) to detect Helicobacter pylori infection and clarithromycin resistance genotype in biopsies obtained from symptomatic children.

  6. Phenotypic and genotypic correlates of daptomycin-resistant methicillin-susceptible Staphylococcus aureus clinical isolates.

    Science.gov (United States)

    Kang, Kyoung-Mi; Mishra, Nagendra N; Park, Kun Taek; Lee, Gi-Yong; Park, Yong Ho; Bayer, Arnold S; Yang, Soo-Jin

    2017-02-01

    Daptomycin (DAP) has potent activity in vitro and in vivo against both methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) strains. DAP-resistance (DAP-R) in S. aureus has been mainly observed in MRSA strains, and has been linked to single nucleotide polymorphisms (SNPs) within the mprF gene leading to altered cell membrane (CM) phospholipid (PL) profiles, enhanced positive surface charge, and changes in CM fluidity. The current study was designed to delineate whether these same genotypic and phenotypic perturbations are demonstrated in clinically-derived DAP-R MSSA strains. We used three isogenic DAP-susceptible (DAP-S)/DAP-R strainpairs and compared: (i) presence of mprF SNPs, (ii) temporal expression profiles of the two key determinants (mprF and dltABCD) of net positive surface charge, (iii) increased production of mprF-dependent lysinylated-phosphatidylglycerol (L-PG), (iv) positive surface charge assays, and (v) susceptibility to cationic host defense peptides (HDPs) of neutrophil and platelet origins. Similar to prior data in MRSA, DAP-R (vs DAP-S) MSSA strains exhibited hallmark hot-spot SNPs in mprF, enhanced and dysregulated expression of both mprF and dltA, L-PG overproduction, HDP resistance and enhanced positive surface charge profiles. However, in contrast to most DAP-R MRSA strains, there were no changes in CM fluidity seen. Thus, charge repulsion via mprF-and dlt-mediated enhancement of positive surface charge may be the main mechanism to explain DAP-R in MSSA strains.

  7. Effects of Temperature Stresses on the Resistance of Chickpea Genotypes and Aggressiveness of Didymella rabiei Isolates

    Directory of Open Access Journals (Sweden)

    Seid Ahmed Kemal

    2017-09-01

    Full Text Available Chickpea (Cicer arietinum L. is an important food and rotation crop in many parts of the world. Cold (freezing and chilling temperatures and Ascochyta blight (Didymella rabiei are the major constraints in chickpea production. The effects of temperature stresses on chickpea susceptibility and pathogen aggressiveness are not well documented in the Cicer-Didymella pathosystem. Two experiments were conducted under controlled conditions using chickpea genotypes and pathogen isolates in 2011 and 2012. In Experiment 1, four isolates of D. rabiei (AR-01, AR-02, AR-03 and AR-04, six chickpea genotypes (Ghab-1, Ghab-2, Ghab-3, Ghab-4, Ghab-5 and ICC-12004 and four temperature regimes (10, 15, 20, and 25°C were studied using 10 day-old seedlings. In Experiment 2, three chickpea genotypes (Ghab-1, Ghab-2, and ICC-12004 were exposed to 5 and 10 days of chilling temperature exposure at 5°C and non-exposed seedlings were used as controls. Seedlings of the three chickpea genotypes were inoculated with the four pathogen isolates used in Experiment 1. Three disease parameters (incubation period, latent period and disease severity were measured to evaluate treatment effects. In Experiment 1, highly significant interactions between genotypes and isolates; genotypes and temperature; and isolate and temperature were observed for incubation and latent periods. Genotype x isolate and temperature x isolate interactions also significantly affected disease severity. The resistant genotype ICC-12004 showed long incubation and latent periods and low disease severity at all temperatures. The highly aggressive isolate AR-04 caused symptoms, produced pycnidia in short duration as well as high disease severity across temperature regimes, which indicated it is adapted to a wide range of temperatures. Short incubation and latent periods and high disease severity were observed on genotypes exposed to chilling temperature. Our findings showed that the significant interactions of

  8. Inference of antibiotic resistance and virulence among diverse group A Streptococcus strains using emm sequencing and multilocus genotyping methods.

    Directory of Open Access Journals (Sweden)

    David Metzgar

    Full Text Available BACKGROUND: Group A Streptococcus pyogenes (GAS exhibits a high degree of clinically relevant phenotypic diversity. Strains vary widely in terms of antibiotic resistance (AbR, clinical severity, and transmission rate. Currently, strain identification is achieved by emm typing (direct sequencing of the genomic segment coding for the antigenic portion of the M protein or by multilocus genotyping methods. Phenotype analysis, including critical AbR typing, is generally achieved by much slower and more laborious direct culture-based methods. METHODOLOGY/PRINCIPAL FINDINGS: We compare genotype identification (by emm typing and PCR/ESI-MS with directly measured phenotypes (AbR and outbreak associations for 802 clinical isolates of GAS collected from symptomatic patients over a period of 6 years at 10 military facilities in the United States. All independent strain characterization methods are highly correlated. This shows that recombination, horizontal transfer, and other forms of reassortment are rare in GAS insofar as housekeeping genes, primary virulence and antibiotic resistance determinants, and the emm gene are concerned. Therefore, genotyping methods offer an efficient way to predict emm type and the associated AbR and virulence phenotypes. CONCLUSIONS/SIGNIFICANCE: The data presented here, combined with much historical data, suggest that emm typing assays and faster molecular methods that infer emm type from genomic signatures could be used to efficiently infer critical phenotypic characteristics based on robust genotype: phenotype correlations. This, in turn, would enable faster and better-targeted responses during identified outbreaks of constitutively resistant or particularly virulent emm types.

  9. Genotypic detection of rifampicin and isoniazid resistant Mycobacterium tuberculosis strains by DNA sequencing: a randomized trial

    Directory of Open Access Journals (Sweden)

    El mashad Noha

    2009-01-01

    Full Text Available Abstract Background Tuberculosis is a growing international health concern. It is the biggest killer among the infectious diseases in the world today. Early detection of drug resistance allows starting of an appropriate treatment. Resistance to drugs is due to particular genomic mutations in specific genes of Mycobacterium tuberculosis(MTB. The aim of this study was to identify the presence of Isoniazid (INH and Rifampicin(RIF drug resistance in new and previously treated tuberculosis (TB cases using DNA sequencing. Methods This study was carried out on 153 tuberculous patients with positive Bactec 460 culture for acid fast bacilli. Results Of the 153 patients, 105 (68.6% were new cases and 48 (31.4% were previously treated cases. Drug susceptibility testing on Bactec revealed 50 resistant cases for one or more of the first line antituberculous. Genotypic analysis was done only for rifampicin resistant specimens (23 cases and INH resistant specimens (26 cases to detect mutations responsible for drug resistance by PCR amplification of rpoB gene for rifampicin resistant cases and KatG gene for isoniazid resistant cases. Finally, DNA sequencing was done for detection of mutation within rpoB and KatG genes. Genotypic analysis of RIF resistant cases revealed that 20/23 cases (86.9% of RIF resistance were having rpoB gene mutation versus 3 cases (13.1% having no mutation with a high statistical significant difference between them (P Conclusion We can conclude that rifampicin resistance could be used as a useful surrogate marker for estimation of multidrug resistance. In addition, Genotypic method was superior to that of the traditional phenotypic method which is time-consuming taking several weeks or longer.

  10. Chloramphenicol- and tetracycline-resistant uropathogenic Escherichia coli (UPEC) exhibit reduced virulence potential.

    Science.gov (United States)

    Starcic Erjavec, Marjanca; Rijavec, Matija; Krizan-Hergouth, Veronika; Fruth, Angelika; Zgur-Bertok, Darja

    2007-11-01

    It is well documented that uropathogenic Escherichia coli (UPEC) isolates resistant to nalidixic acid have reduced virulence potential. Our goal was to assess whether UPEC isolates resistant to chloramphenicol, tetracycline and streptomycin also exhibit reduced virulence potential. Among 110 human UPEC isolates, the prevalences of the virulence factors fimH, papC, papGII, papGIII, sfa/focDE, afa, hlyA, cnf1, usp, ibeA, fyuA, iroN, iucD, ireA, and K1 and K5 capsules as well as of pathotypes, phylogenetic groups, O antigens and a pathogenicity island (PAI) marker were compared between chloramphenicol-, tetracycline-, streptomycin- and, as a control, nalidixic acid-resistant and -susceptible strains. Our findings show that among human UPEC isolates, not only nalidixic acid-resistant but also chloramphenicol- and tetracycline-resistant isolates have reduced virulence potential compared with susceptible strains. To our knowledge, this is the first report of a statistically significant reduction in virulence traits among chloramphenicol- and tetracycline-resistant isolates.

  11. Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening).

    Science.gov (United States)

    Dutt, Manjul; Barthe, Gary; Irey, Michael; Grosser, Jude

    2015-01-01

    Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB), a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars 'Hamlin' and 'Valencia' expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2) promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree.

  12. Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening.

    Directory of Open Access Journals (Sweden)

    Manjul Dutt

    Full Text Available Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB, a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars 'Hamlin' and 'Valencia' expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2 promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree.

  13. Resistance of soybean genotypes to Bemisia tabaci (Genn.) Biotype B (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Vieira, S S; Bueno, A F; Boff, M I C; Bueno, R C O F; Hoffman-Campo, C B

    2011-01-01

    The silverleaf whitefly Bemisia tabaci (Genn.) biotype B has become a serious problem for soybean cultivation because it can significantly reduce soybean productivity. The use of soybean cultivars resistant to whitefly attack is an important strategy in an integrated pest management (IPM) program. This study evaluated the preference for oviposition and colonization by B. tabaci biotype B on different soybean genotypes. In the free-choice test, the genotypes studied were 'IAC 17' and 'IAC 19' as the standards for resistance and 'IAC Holambra Stwart' as the standard for susceptibility, as well as BABR01-0492, BABR01-0173, BABR01-1259, BABR01-1576, BABR99-4021HC, BABR99-4021HP, 'Barreiras', 'Conquista', 'Corisco', 'BRS Gralha', PI274454, PI227687, and PI171451. In the no-choice test, the four best genotypes selected in the free-choice test, in addition to the susceptible and resistant standards were evaluated. Our data indicated 'Barreiras' as the most resistant genotype against B. tabaci biotype B. 'BRS Gralha', which was the least attractive to whitefly adults in the free-choice test, did not show resistance to insect attack when they were confined in cages in the no-choice test. Despite the high number of eggs observed, BABR01-1576 and BABR99-4021HC showed a reduced number of nymphs, indicating antibiosis. The genotypes with a high level of resistance can be used as a tool against B. tabaci in IPM or as a source of resistance in plant-breeding programs.

  14. Genotypic resistance tests in the management of the HIV-infected patient at virological failure.

    Science.gov (United States)

    Aceti, Antonio; Carosi, Giampiero

    2003-01-01

    Witness for the prosecution: The IAS-USA and Euro-Resistance Group HIV guidelines recommend the use of resistance testing for all patients experiencing treatment failure for whom therapy change is being considered. However, these assays suffer from several limitations (problems in sensitivity, specificity, complexity of interpretation, cost) and the results of the prospective studies evaluating genotype-guided treatment in HIV patients failing antiretroviral treatment are inconclusive and partially contrasting (virological benefit is short-term). On this basis, incorporating genotypic resistance assays into the clinical management of HIV patients experiencing first treatment failure is not a sufficiently evidence-based practice. Witness for the defence: Highly active antiretroviral therapy (HAART) has markedly improved the prognosis of HIV-infected patients by controlling HIV replication. However, HAART fails to control HIV replication in an increasing number of patients as a result of a complex array of causes. There is now substantial evidence that the emergence of drug resistance is a leading cause (as well as consequence) of antiretroviral therapy failure. Moreover, HIV drug resistance can be transmitted and this can favour initial treatment failure. Several retrospective and prospective studies have indicated that both genotypic and phenotypic HIV-1 drug resistance testing results are associated with, or predictive of, the virological outcome. As a consequence, international guidelines have soundly recommended the use of resistance testing to guide treatment choices after virological failure. The rationale and advantages of using such testing after first virological failure will be discussed.

  15. Genotype MTBDR plus assay for molecular detection of rifampicin and isoniazid resistance in Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Soniya Sharma

    2014-01-01

    Full Text Available Aim: This study was performed for the rapid identification of Mycobacterium tuberculosis complex and its resistance to rifampicin and isoniazid, directly from the sputum samples of pulmonary tuberculosis patients. Materials and Methods: A commercially available genotype MTBDR plus assay was used for the identification and detection of mutations in Mycobacterial isolates. A total of 100 sputum samples of pulmonary tuberculosis patients were analyzed by using the genotype MTBDR plus assay. The MTBDR plus assay is designed to detect the mutations in the hotspot region of rpoB gene, katG and regulatory region of inhA gene. Results: The genotype MTBDR plus assay detected 22% multidrug resistant (MDR, 2% rifampicin (RMP monoresistant and 1% isoniazid (INH monoresistant isolates. In 22 MDR isolates, the codons most frequently involved in RMP-associated mutations were codon 531 (54.55%, 516 (31.82% and 526 (13.63%, and 90.90% of MDR isolates showed KatG S315T mutations and 9.1% showed inhA C-15T mutations associated with INH resistance. Conclusion: The new genotype MTBDR plus assay represents a rapid, reliable tool for the detection of MDR-TB, wherein results are obtained in 5 h allowing early and appropriate treatment, which is essential to cut the transmission path and reduce the spread of MDR-TB. The genotype MTBDR plus assay can readily be included in a routine laboratory work for the early diagnosis and control of MDR-TB.

  16. Metal-free, single-polymer device exhibits resistive memory effect

    KAUST Repository

    Bhansali, Unnat Sampatraj

    2013-12-23

    All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

  17. Cellular Responses of Resistant and Susceptible Soybean Genotypes Infected with Meloidogyne arenaria Races 1 and 2.

    Science.gov (United States)

    Pedrosa, E M; Hussey, R S; Boerma, H R

    1996-06-01

    The cellular responses induced by Meloidogyne arenaria races 1 and 2 in three soybean genotypes, susceptible CNS, resistant Jackson, and resistant PI 200538, were examined by light microscopy 20 days after inoculation. Differences in giant-cell development were greater between races than among the soybean genotypes. M. arenaria race 1 stimulated small, poorly formed giant-cells in contrast with M. arenaria race 2, which induced well-developed, thick-walled, multinucleate giant-cells. The number of nuclei per giant-celt was variable, but fewer nuclei were usually present in giant-cells induced by race 1 (mean 16 nuclei) than in giant-cells induced by race 2 (mean 41 nuclei). Differences observed in giant-cell development were related to differences in growth and maturation of M. arenaria races 1 and 2 and host suitability of the soybean genotypes.

  18. Multicenter Quality Control of Hepatitis C Virus Protease Inhibitor Resistance Genotyping

    OpenAIRE

    Vallet, Sophie; Larrat, Sylvie; Laperche, Syria; Le Guillou-Guillemette, Hélène; Legrand-Abravanel, Florence; Bouchardeau, Françoise; Pivert, Adeline; Henquell, Cécile; Mirand, Audrey; André-Garnier, Elisabeth; Giordanengo, Valérie; Lagathu, Gisèle; Thibault, Vincent; Scholtes, Caroline; Schvoerer, Evelyne

    2013-01-01

    Hepatitis C virus (HCV) protease inhibitor resistance-associated substitutions are selected during triple-therapy breakthrough. This multicenter quality control study evaluated the expertise of 23 French laboratories in HCV protease inhibitor resistance genotyping. A panel of 12 well-defined blinded samples comprising two wild-type HCV strains, nine transcripts from synthetic NS3 mutant samples or from clinical strains, and one HCV RNA-negative sample was provided to the participating laborat...

  19. Context matters — the complex interplay between resistome genotypes and resistance phenotypes

    DEFF Research Database (Denmark)

    Dantas, Gautam; Sommer, Morten

    2012-01-01

    Application of metagenomic functional selections to study antibiotic resistance genes is revealing a highly diverse and complex network of genetic exchange between bacterial pathogens and environmental reservoirs, which likely contributes significantly to increasing resistance levels in pathogens....... In some cases, clinically relevant resistance genes have been acquired from organisms where their native function is not antibiotic resistance, and which may not even confer a resistance phenotype in their native context. In this review, we attempt to distinguish the resistance phenotype from...... the resistome genotype, and we highlight examples of genes and their hosts where this distinction becomes important in order to understand the relevance of environmental niches that contribute most to clinical problems associated with antibiotic resistance....

  20. Lamivudine resistance mutations in patients infected with hepatitis B virus genotype D

    Institute of Scientific and Technical Information of China (English)

    Orhan Y(l)ld(l)z; Bilgehan Aygen; Nese Demirtürk; Tuna Demirdal; Dilara Inan; Taner Y(l)ld(l)rmak; Arzu Kantürk; Ediz Tütüncü

    2011-01-01

    AIM: To determine the distribution of viral genotypes for primary or acquired lamivudine resistance. METHODS: A total of 283 patients with chronic hepatitis B virus (HBV) infection (245 patients with chronic hepatitis B and 38 inactive hepatitis B surface antigen carriers) were included in the study. The HBV genotype was determined by using quantitative real-time polymerase chain reaction and sequence analysis, and tyrosine-methionine-aspartate-aspartate (YMDD) motif mutations were determined using the reverse transcriptase hybridization method. RESULTS: Lamivudine resistance was determined in a total of 25 (10.7%) chronic hepatitis B patients. Eight subjects (4%) had primary resistance to lamivudine, and 17 (53.1%) had secondary resistance to lamivudine. Genotype D, which was isolated from 267 of the patients with chronic HBV infection, was the dominant genotype in Turkey.CONCLUSION: Identification of YMDD motif mutations should have a positive impact on the selection of proper antiviral medication for patients, even for those who are nucleoside na(i)ve.

  1. Evaluating the role of root citrate exudation as a mechanism of aluminium resistance in maize genotypes

    NARCIS (Netherlands)

    Mariano, E.D.; Keltjens, W.G.

    2003-01-01

    Organic anion exudation by roots as a mechanism of aluminium (Al) resistance has been intensively studied lately. In the present study, we evaluated qualitative and quantitative aspects of root exudation of organic anions in maize genotypes of distinct sensitivity to Al in response to Al exposure. R

  2. 21 CFR 866.3950 - In vitro human immunodeficiency virus (HIV) drug resistance genotype assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false In vitro human immunodeficiency virus (HIV) drug... OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3950 In vitro human immunodeficiency virus (HIV) drug resistance genotype assay....

  3. Epidemiology and genotypic characteristics of Methicillin-Resistant Staphylococcus aureus strains of porcine origin

    Science.gov (United States)

    The main goal of this study was to determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA), particularly livestock-associated (LA)-MRSA in pigs and pork. Genotypic relatedness of isolates on-farm, at slaughter and retail was assessed. Paired nasal and peri-anal swab samples we...

  4. Genotype x environment interaction and growth stability of several elm clones resistant to Dutch elm disease

    Science.gov (United States)

    Alberto Santini; Francesco Pecori; Alessia L. Pepori; Luisa Ghelardini

    2012-01-01

    The elm breeding program carried out in Italy at the Institute of Plant Protection - Consiglio Nazionale delle Ricercje (CNR) during the last 40 years aimed to develop Dutch elm disease (DED)-resistant elm selections specific to the Mediterranean environment. The need for genotypes adapted to Mediterranean conditions was evident from the poor performance of the Dutch...

  5. Nematicides enhance growth and yield of rotylenchulus reniformis resistant cotton genotypes.

    Science.gov (United States)

    Schrimsher, Drew W; Lawrence, Kathy S; Sikkens, Roelof B; Weaver, David B

    2014-12-01

    Rotylenchulus reniformis resistant LONREN-1×FM966 breeding lines developed at Auburn University have demonstrated that the nematode resistance is accompanied by severe stunting, limited growth, and low yields. The objectives of this study were to evaluate the effects of applying nematicides to selected LONREN breeding lines on R. reniformis nematode populations, plant stunting, and yield. Four resistant breeding lines from the LONREN-1×FM966 cross, one susceptible line from the LONREN-1×FM966 cross, as well as LONREN-1, BARBREN-713, and the susceptible cultivar DP393 were evaluated with and without nematicides in the presence of R. reniformis. In the greenhouse, nematicides increased plant height across all genotypes compared with no nematicide. Rotylenchulus reniformis populations were 50% lower in the resistant lines compared with the susceptible lines at 45 days after planting (DAP). In microplot and field trials, the phenotypic stunting of all genotypes was reduced by aldicarb with increases in plant heights at 30 and 75 DAP. Increases in yields were evident across all genotypes treated with aldicarb. In all three trial environments, BARBREN-713 outperformed the LONREN-derived lines as well as 'DP393' in seed cotton yields, while having significantly lower R. reniformis egg densities than the susceptible genotypes.

  6. Differential resistance reaction of maize genotypes to maize stem borer (Chilo partellus Swinhoe at Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Ghanashyam Bhandari

    2016-12-01

    Full Text Available Maize stem borer (MSB, Chilo partellus Swinhoe, Lepidoptera: Pyralidae is one of the most important insect pest of maize in Nepal. Host plant resistance is the cost-effective, ecologically sound and stable approach to reduce damage by stem borers. Forty four maize genotypes were screened for resistance to maize stem borer at the research field of National Maize Research Program, Rampur during spring seasons (March to June of two consecutive years 2013 and 2014. The maize genotypes were evaluated in randomized complete block design with three replications and data were collected on foliar damage rating, tunnel length and number of exit holes made by the borer. The foliar damage and tunnel length damage were significant for genotypes for both the years. The exit holes were not significant in 2013 but significant in 2014 ranging from 2-6 scale. The foliar rating ranged from 2 to 5.5 in 2013 and 1.1 to 4.5 in 2014 on a 1-9 rating scale. The highly resistant genotypes (10 cm scale. The least susceptible genotypes (<5 cm were RampurSO3F8, RampurSO3FQ02 and RampurS10F18. The genotypes having least exit holes (2.0 in 2014 were RampurSO3F8, RampurSO3FQ02, RampurS10F18. Thus less damage parameters were observed in R-POP-2, RML-5/RML-8, RampurSO3F8, RampurSO3FQ02 and RampurS10F18 and therefore they can be used as parents or as sources of resistance in breeding program.

  7. Phenotypic and genotypic variation among Capsicum annuum recombinant inbred lines resistant to bacterial spot.

    Science.gov (United States)

    Moreira, S O; Rodrigues, R; Oliveira, H S; Medeiros, A M; Sudré, C P; Gonçalves, L S A

    2013-04-17

    A breeding program carried out under Brazilian growing conditions to obtain Capsicum annuum cultivars with disease resistance to bacterial spot (BS) produced 8 promising recombinant inbred lines (RILs). The present study aimed to characterize these RILs using phenotypic descriptors and molecular markers (inter-simple sequence repeat) and to confirm their resistance to BS. Twenty-two phenotypic descriptors and 15 inter-simple sequence repeat primers were used to characterize the RILs. The parent, UENF 1381, which is resistant to BS, and 'Casca Dura Ikeda', a traditional cultivar, were used as standards. Variability among genotypes was observed considering either binary or multicategorical characteristics, such as fruit length, fruit diameter, and fruit longitudinal and transversal section. Such variability in fruit traits can be exploited to develop new genotypes with BS resistance for various types of market consumption. RILs numbered 1, 3, and 6 were the most homogenous, whereas those coded 2, 5, 8, and 11 had the same level of heterogeneity as that observed in 'Casca Dura Ikeda'. Molecular analysis clustered the genotypes into 5 groups, with RILs 1, 2, 3, and 5 allocated in isolated groups. RILs 1, 2, 6, and 8 confirmed resistance to BS. Considering homogeneity level and BS resistance, RILs 1 and 6 were suitable for use as pre-cultivars in final tests to register and release two new C. annuum cultivars.

  8. Defining Multidrug-Resistant Tuberculosis: Correlating GenoType MTBDRplus Assay Results with Minimum Inhibitory Concentrations

    Science.gov (United States)

    Kambli, Priti; Ajbani, Kanchan; Sadani, Meeta; Nikam, Chaitali; Shetty, Anjali; Udwadia, Zarir; Georghiou, Sophia B; Rodwell, Timothy C; Catanzaro, Antonino; Rodrigues, Camilla

    2015-01-01

    This study correlates Minimum Inhibitory Concentrations (MICs) of rifampicin (RIF) and isoniazid (INH) with GenoType MTBDRplus assay results for drug-resistant Mycobacterium tuberculosis (MTB) clinical isolates. MICs of RIF and INH were established for 84 and 90 isolates, respectively, testing six concentrations of each drug. Genotypic resistance to each drug was determined by GenoType MTBDRplus assay with 50 representative mutations confirmed by pyrosequencing, with mutations in the rpoB gene associated with RIF-resistance and mutations in the katG and/or inhA genes associated with INH-resistance. Based upon the correlation of MICs with specific genetic profiles, relative resistance levels were established for each isolate. Results indicate that MTB phenotypic resistance, currently based upon the testing of isolate susceptibility to a single drug concentration, may be more accurately profiled via quantitative MICs, and therefore the correlation of molecular diagnostic results with specific MICs may allow for more optimal treatment of infections. PMID:25749461

  9. Genotypic responses and diallel analysis for an early resistance test to Sclerotinia sclerotiorum in sunflower

    Directory of Open Access Journals (Sweden)

    Castaño Fernando

    2002-11-01

    Full Text Available The evaluation of sunflower genotypic performance against Sclerotinia sclerotiorum infections is important for understanding its usefulness as source of resistance. In the field, artificial and natural resistance tests provide important information that can be used in the selection of the best materials, however the procedures for resistance tests are usually both expensive and laborious. This work describes the performance of sunflower genotypes of broad genetic base at an early stage of plant development using a resistance test carried out under controlled conditions in the greenhouse. Statistical analysis detected highly significant genotypic responses and the combined abilities effects among the evaluated populations and their offspring, obtained by a diallel crossing system method 2 for dead seedlings (% at 25 days after S. sclerotiorum infection on the basal stem. The methodology allowed superior parents to be detected and crosses to be furthered in the selection for S. sclerotiorum resistance. The usefulness of the evaluated genetic materials and the early resistance test in sunflower breeding plans is discussed.

  10. Specific adjustments in grapevine leaf proteome discriminating resistant and susceptible grapevine genotypes to Plasmopara viticola

    DEFF Research Database (Denmark)

    Figueiredo, Andreia; Martins, Joana; Sebastiana, Mónica

    2017-01-01

    differentiating the resistant genotype. Lipid associated signalling events, particularly related to jasmonates appear also to play a major role in the establishment of resistance. The findings from this study contribute to a better understanding of genotype-specific differences that account for a successful...

  11. Large-scale survey for novel genotypes of Plasmodium falciparum chloroquine-resistance gene pfcrt

    Directory of Open Access Journals (Sweden)

    Takahashi Nobuyuki

    2012-03-01

    Full Text Available Abstract Background In Plasmodium falciparum, resistance to chloroquine (CQ is conferred by a K to T mutation at amino acid position 76 (K76T in the P. falciparum CQ transporter (PfCRT. To date, at least 15 pfcrt genotypes, which are represented by combinations of five amino acids at positions 72-76, have been described in field isolates from various endemic regions. To identify novel mutant pfcrt genotypes and to reveal the genetic relatedness of pfcrt genotypes, a large-scale survey over a wide geographic area was performed. Methods Sequences for exon 2 in pfcrt, including known polymorphic sites at amino acid positions 72, 74, 75 and 76, were obtained from 256 P. falciparum isolates collected from eight endemic countries in Asia (Bangladesh, Cambodia, Lao P.D.R., the Philippines and Thailand, Melanesia (Papua New Guinea and Vanuatu and Africa (Ghana. A haplotype network was constructed based on six microsatellite markers located -29 kb to 24 kb from pfcrt in order to examine the genetic relatedness among mutant pfcrt genotypes. Results In addition to wild type (CVMNK at positions 72-76, four mutant pfcrt were identified; CVIET, CVIDT, SVMNT and CVMNT (mutated amino acids underlined. Haplotype network revealed that there were only three mutant pfcrt lineages, originating in Indochina, Philippines and Melanesia. Importantly, the Indochina lineage contained two mutant pfcrt genotypes, CVIET (n = 95 and CVIDT (n = 14, indicating that CVIDT shares a common origin with CVIET. Similarly, one major haplotype in the Melanesian lineage contained two pfcrt genotypes; SVMNT (n = 71 and CVMNT (n = 3. In Africa, all mutant pfcrt genotypes were the CVIET of the Indochina lineage, probably resulting from the intercontinental migration of CQ resistance from Southeast Asia. Conclusions The number of CQ-mutant lineages observed in this study was identical to that found in previous studies. This supports the hypothesis that the emergence of novel CQ resistance

  12. Jurkat/A4 cells with multidrug resistance exhibit reduced sensitivity to quercetin.

    Science.gov (United States)

    Philchenkov, A; Zavelevich, M; Savinska, L; Blokhin, D

    2010-07-01

    While multidrug resistance of cancer cells is a well-known phenomenon, little is known on the cross resistance between cytotoxic chemotherapeutical agents and unrelated substances such as natural flavonoids. To compare the effects of cytotoxic drug, vepeside and natural flavonoid, quercetin in Jurkat cells and their multidrug-resistant subline Jurkat/A4, in particular to analyze the effector mechanisms of apoptosis and the profiles of several pro- and antiapoptotic proteins in these cells upon exposure to vepeside or quercetin. Apoptosis and poly (ADP-ribose) polymerase cleavage were assessed by flow cytometry. Expression of apoptosis-related proteins was analyzed by Western blotting. Jurkat/A4 cells are less sensitive to antiproliferative effects of quercetin as compared with the parental Jurkat cell line. While vepeside as well as quercetin initially induces apoptosis in both cell lines, the following survival of the exposed cells is essentially different. In resistant Jurkat/A4 cells, vepeside or quercetin treatment activates significantly less caspase-9 and -3 as compared with that in the parental cells. The expression of Bad and BNip1 proteins in Jurkat/A4 cells is lower than in the parental cell line. At the same time, XIAP and CAS levels in Jurkat/A4 cells increase. Upon apoptosis induction, XIAP and CAS levels in Jurkat cells decrease, this effect being negligible in resistant cells. Multidrug-resistant Jurkat/A4 cells exhibit reduced sensitivity to cytotoxic effects of quercetin. The expression profile of Jurkat/A4 cells is characterized by the increased levels of XIAP and CAS representing the endogenous inhibitors of apoptosis.

  13. Epoxy Resin/Nano Ni@C Composites Exhibiting NTC Effect with Tunable Resistivity

    Institute of Scientific and Technical Information of China (English)

    Bangwen Zhang; Baowei Li; Changsheng Xie

    2009-01-01

    Epoxy resin/Ni@C nanoparticle composites with aligned microstructure were prepared by using a procedure of magnetic field assisted curing. The results show that the resistivity of composites exhibits negative temperature coefficient (NTC) effect above room temperature, and can be adjusted by varying the content filler and the magnitude of magnetic field applied. Hill's quantum tunneling model was modified to understand the electrical conduction mechanism in the composites. It shows that the NTC effect ascribes to the dominant thermal activated tunneling transport of electron across adjacent nanoparticles, as well as the low thermal expansivity of epoxy resin matrix.

  14. A single-nucleotide-polymorphism-based genotyping assay for simultaneous detection of different carbendazim-resistant genotypes in the Fusarium graminearum species complex

    Science.gov (United States)

    Zhang, Hao; Brankovics, Balázs; van der Lee, Theo A.J.; Waalwijk, Cees; van Diepeningen, Anne A.D.; Xu, Jin; Xu, Jingsheng

    2016-01-01

    The occurrence resistance to methyl benzimidazole carbamates (MBC)-fungicides in the Fusarium graminearum species complex (FGSC) is becoming a serious problem in the control of Fusarium head blight in China. The resistance is caused by point mutations in the β2-tubulingene. So far, five resistant genotypes (F167Y, E198Q, E198L, E198K and F200Y) have been reported in the field. To establish a high-throughput method for rapid detection of all the five mutations simultaneously, an efficient single-nucleotide-polymorphism-based genotyping method was developed based on the Luminex xMAP system. One pair of amplification primers and five allele specific primer extension probes were designed and optimized to specially distinguish the different genotypes within one single reaction. This method has good extensibility and can be combined with previous reported probes to form a highly integrated tool for species, trichothecene chemotype and MBC resistance detection. Using this method, carbendazim resistant FGSC isolates from Jiangsu, Anhui and Sichuan Province in China were identified. High and moderate frequencies of resistance were observed in Jiangsu and Anhui Province, respectively. Carbendazim resistance in F. asiaticum is only observed in the 3ADON genotype. Overall, our method proved to be useful for early detection of MBC resistance in the field and the result aids in the choice of fungicide type. PMID:27812414

  15. GENETIC DIVERSITY OF S3 MAIZE GENOTYPES RESISTANT TO DOWNY MILDEW BASED ON SSR MARKERS

    Directory of Open Access Journals (Sweden)

    Amran Muis

    2016-02-01

    Full Text Available The compulsory requirement for releasing new high yielding maize varieties is resistance to downy mildew. The study aimed to determine the level of homozygosity, genetic diversity, and  genetic distance of 30 S3 genotypes of maize. Number of primers to be used were 30 polymorphic SSR loci which are distributed over the entire maize genomes. The S3 genotypes used were resistant to downy mildew with homozygosity level of >80%, genetic distance between the test and tester strains >0.7, and anthesis silking interval (ASI between inbred lines and tester lines was maximum 3 days. The results showed that 30 SSR primers used were spread evenly across the maize genomes which were manifested in the representation of SSR loci on each chromosome of a total of 10 chromosomes. The levels of polymorphism ranged from 0.13 to 0.78, an average of 0.51, and the number of alleles ranged from 2 to 8 alleles per SSR locus, an average of 4 alleles per SSR locus. The size of nucleotides in each locus also varied from 70 to 553 bp. Cophenetic correlation value (r at 0.67 indicated that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA was less reliable for differentiating genotypes in five groups. Of the total of 30 genotypes analyzed, 17 genotypes had homozygosity level of >80% so it can be included in the hybrid assembly program.

  16. Multicenter quality control of hepatitis C virus protease inhibitor resistance genotyping.

    Science.gov (United States)

    Vallet, Sophie; Larrat, Sylvie; Laperche, Syria; Le Guillou-Guillemette, Hélène; Legrand-Abravanel, Florence; Bouchardeau, Françoise; Pivert, Adeline; Henquell, Cécile; Mirand, Audrey; André-Garnier, Elisabeth; Giordanengo, Valérie; Lagathu, Gisèle; Thibault, Vincent; Scholtes, Caroline; Schvoerer, Evelyne; Gaudy-Graffin, Catherine; Maylin, Sarah; Trimoulet, Pascale; Brochot, Etienne; Hantz, Sébastien; Gozlan, Joël; Roque-Afonso, Anne-Marie; Soussan, Patrick; Plantier, Jean-Christophe; Charpentier, Charlotte; Chevaliez, Stéphane; Colson, Philippe; Mackiewicz, Vincent; Aguilera, Lina; Rosec, Sylvain; Gouriou, Stéphanie; Magnat, Nelly; Lunel-Fabiani, Françoise; Izopet, Jacques; Morand, Patrice; Payan, Christopher; Pawlotsky, Jean-Michel

    2013-05-01

    Hepatitis C virus (HCV) protease inhibitor resistance-associated substitutions are selected during triple-therapy breakthrough. This multicenter quality control study evaluated the expertise of 23 French laboratories in HCV protease inhibitor resistance genotyping. A panel of 12 well-defined blinded samples comprising two wild-type HCV strains, nine transcripts from synthetic NS3 mutant samples or from clinical strains, and one HCV RNA-negative sample was provided to the participating laboratories. The results showed that any laboratory with expertise in sequencing techniques should be able to provide reliable HCV protease inhibitor resistance genotyping. Only a 0.7% error rate was reported for the amino acid sites studied. The accuracy of substitution identification ranged from 75% to 100%, depending on the laboratory. Incorrect results were mainly related to the methodology used. The results could be improved by changing the primers and modifying the process in order to avoid cross-contamination. This study underlines the value of quality control programs for viral resistance genotyping, which is required prior to launching observational collaborative multicenter studies on HCV resistance to direct-acting antiviral agents.

  17. Genotypes of Mycobacterium tuberculosis in patients at risk of drug resistance in Bolivia.

    Science.gov (United States)

    Monteserin, Johana; Camacho, Mirtha; Barrera, Lucía; Palomino, Juan Carlos; Ritacco, Viviana; Martin, Anandi

    2013-07-01

    Bolivia ranks among the 10 Latin American countries with the highest rates of tuberculosis (TB) and multidrug resistant (MDR) TB. In view of this, and of the lacking information on the population structure of Mycobacterium tuberculosis in the country, we explored genotype associations with drug resistance and clustering by analyzing isolates collected in 2010 from 100 consecutive TB patients at risk of drug resistance in seven of the nine departments in which Bolivia is divided. Fourteen isolates were MDR, 29 had other drug resistance profiles, and 57 were pansusceptible. Spoligotype family distribution was: Haarlem 39.4%, LAM 26.3%, T 22.2%, S 2.0%, X 1.0%, orphan 9.1%, with very low intra-family diversity and absence of Beijing genotypes. We found 66 different MIRU-VNTR patterns; the most frequent corresponded to Multiple Locus Variable Analysis (MLVA) MtbC15 patterns 860, 372 and 873. Twelve clusters, each with identical MIRU-VNTR and spoligotypes, gathered 35 patients. We found no association of genotype with drug resistant or MDR-TB. Clustering associated with SIT 50 and the H3 subfamily to which it belongs (pBolivia. However, results should be taken cautiously because the sample is small and includes a particular subset of M. tuberculosis population. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. DRUG RESISTANCE, VIABILITY AND VIRULENCE IN VITRO ОF MYCOBACTERIUM TUBERCULOSIS STRAINS OF DIFFERENT GENOTYPES

    Directory of Open Access Journals (Sweden)

    O. A. Manicheva

    2011-01-01

    Full Text Available Abstract. The drug resistance, mutation spectrum caused resistance to rifampicin and isoniazid, viability, cytotoxicity were studied as well as 111 clinical isolates of Mycobacterium tuberculosis (MBT were genotyped. Spoligotyping revealed 28 spoligotypes; the greatest number of strains belonged to genetic families Beijing and LAM. The typing of 59 strains of spoligotype SIT1 (Beijing allowed to differentiate 19 variants of IS6110-RFLP-profiles: 13 of them were individual and 6 were presented by clusters. The clusters А0 and В0 included the greatest number of M. tuberculosis strains — 21 (35,6% and 17 (28,8% accordingly. The high frequency of MLU and SLU of Beijing strains was associated with mutations rpoB Ser531→Leu and katG Ser315→Thr. The strains of M. tuberculosis belonged to another genetic families (T, H, Ural, U have shown drug resistance more often. The level of resistance to isoniazid in vitro in MLU/SLU strains of MBT of different genotypes, especially, was high in case of mixed mutations such as katG Ser315→Thr и inhA_T15. The rates of viability and cytotoxicity of MBT strains of studied genotypes with different spectrum of mutations and phenotypic drug resistance were not substantially distinguished.

  19. [Molecular test Genotype® MTBDRplus, an alternative to rapid detection of multidrug resistance tuberculosis].

    Science.gov (United States)

    Asencios, Luis; Galarza, Marco; Quispe, Neyda; Vásquez, Lucy; Leo, Elena; Valencia, Eddy; Ramírez, Juan; Acurio, Margoth; Salazar, Rosario; Mendoza-Ticona, Alberto; Cáceres, Omar

    2012-03-01

    The Genotype®MTBDRplus molecular test is a method that allows identification of the most frequent mutations associated with resistance to major first-line antituberculosis drugs, Isoniazid (INH) and Rifampicin (RFP). The aim of this study was to evaluate the performance of the molecular test with culture and smear- positive sputum samples. We evaluated 95 cultures and 100 sputum samples with resistance profiles previously determined by the reference method "Agar Plate Proportions" (APP). The molecular test from cultures showed a sensitivity of 100 %, 97,5 % and 96,97 % for RIF, INH and MDR respectively while from sputums the sensitivity was 95,65 %, 96,77 % and 95,24 % for RIF, INH and MDR respectively. We conclude that the molecular test Genotype®MTBDRplus is a very useful tool to detect resistance to isoniazid and rifampicin simultaneously (MDR-TB) in up to 72 hours from sputum samples or cultures.

  20. Use of Genotype MTBDRplus Assay for Diagnosis of Multidrug-Resistant Tuberculosis in Nepal

    Directory of Open Access Journals (Sweden)

    Elina Maharjan

    2017-01-01

    Full Text Available The main aims of this study were to study the patterns of mutations in rpoB, katG, and inhA genes in Mycobacterium tuberculosis strains isolated from patients from Nepal and to evaluate the performance of genotype MTBDRplus assay, taking conventional drug susceptibility testing as gold standard for diagnosis of MDR-TB. A total of 69 Mycobacterium tuberculosis strains isolated from 73 smear positive sputum samples from patients suspected of suffering from multidrug-resistant tuberculosis were used in our study. The drug susceptibility pattern of Mycobacterium tuberculosis isolated from these sputum specimens was determined by using genotype MTBDRplus assay taking conventional drug susceptibility testing as reference. The sensitivity and specificity of the genotype MTBDRplus assay for the detection of MDR-TB were found to be 88.7% and 100%, respectively. 88.7% of the rifampicin resistant isolates had mutations in rpoB gene. Similarly, 79.7% and 9.4% of isoniazid resistant isolates had mutations in katG and inhA genes, respectively. Genotype MTBDRplus assay was found to be very rapid and highly sensitive and specific method for diagnosis of MDR-TB and will be very helpful for early diagnosis of MDR-TB in high tuberculosis burden countries.

  1. Determination of sex and scrapie resistance genotype in preimplantation ovine embryos.

    Science.gov (United States)

    Guignot, Florence; Baril, Gerard; Dupont, Francis; Cognie, Yves; Folch, Jose; Alabart, Jose Luis; Poulin, Naty; Beckers, Jean-Francois; Bed'hom, Bertrand; Babilliot, Jean-Marc; Mermillod, Pascal

    2009-02-01

    The aim of this study was to test the accuracy of genotype diagnosis after pre-amplification of DNA extracted from biopsies obtained by microblade cutting of ovine embryos and to evaluate the viability of biopsied embryos after vitrification/warming and transfer to recipients. Sex and PrP genotypes were determined. Sex diagnosis was done by PCR amplification of ZFX/ZFY and SRY sequences after PEP-PCR while PrP genotype determination was performed after specific pre-amplification of specific target including codons 136, 154 and 171. Embryos were collected at Day 7 after oestrus. Blastocysts and expanded blastocysts were biopsied immediately after collection whereas compacted morulae were biopsied after 24 hr of in vitro culture. Eighty-nine biopsied embryos were frozen by vitrification. Fresh and vitrified whole embryos were kept as control. DNA of biopsies was extracted and pre-amplified. Sex diagnosis was efficient for 96.6% of biopsies and PrP genotyping was determined in 95.8% of codons. After embryo transfer, no significant difference was observed in lambing rate between biopsied, vitrified control and fresh embryos (54.5%, 60% and 66.6%, respectively). Embryo survival rate was not different between biopsied and whole vitrified embryos (P = 0.38). At birth, 96.7% of diagnosed sex and 95.4% of predetermined codons were correct. Lamb PrP profiles were in agreement with parental genotype. PEP-PCR coupled with sex diagnosis and nested PCR coupled with PrP genotype predetermination are very accurate techniques to genotype ovine embryo before transfer. These original results allow planning of selection of resistant genotype to scrapie and sex of offspring before transfer of cryopreserved embryo.

  2. Isolation and characterization of vanA genotype vancomycin-resistant Enterococcus cecorum from retail poultry in Japan.

    Science.gov (United States)

    Harada, Tetsuya; Kawahara, Ryuji; Kanki, Masashi; Taguchi, Masumi; Kumeda, Yuko

    2012-02-15

    The isolation rate of high-level vancomycin-resistant enterococci (VRE) from poultry samples in Japan has increased in recent years. As this raises concerns for the potential spread of genes encoding vancomycin resistance, poultry is routinely screened for VRE. Here, we report the isolation and characterization of a vanA genotype vancomycin-resistant Enterococcus cecorum strain (E. cecorum IPHa84) from retail domestic poultry in September 2009. The species identification was performed by biochemical testing and sequencing of the 16S rRNA and manganese-dependent superoxide dismutase genes. The vancomycin and teicoplanin susceptibility tests showed that E. cecorum IPHa84 was resistant to vancomycin and susceptible to teicoplanin, demonstrating that this isolate was VanB phenotype-vanA genotype VRE. Moreover, a vanA gene cluster was found in a chromosomally encoded Tn1546-related element, which exhibited the characteristic structure of the prototype Tn1546 element, but contained eight point mutations. The vanS sequence of E. cecorum IPHa84 contained three point mutations and was 100% identical to those of VRE isolated from different broiler droppings in Japan prior to the banning of avoparcin, indicating that the Tn1546-related element may be stable in poultry production environments, even in the absence of selective pressure. The isolation of a novel enterococcal species harboring the vanA gene reconfirms that poultry can serve as a reservoir of VanA-type VRE or vancomycin resistance genes, and suggests that the transmission of these risk factors from poultry to humans through the food chain remains a potential threat in Japan. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Resistant starch content among several sorghum (Sorghum bicolor) genotypes and the effect of heat treatment on resistant starch retention in two genotypes.

    Science.gov (United States)

    Teixeira, Natália de Carvalho; Queiroz, Valéria Aparecida Vieira; Rocha, Maria Clara; Amorim, Aline Cristina Pinheiro; Soares, Thayana Oliveira; Monteiro, Marlene Azevedo Magalhães; de Menezes, Cícero Beserra; Schaffert, Robert Eugene; Garcia, Maria Aparecida Vieira Teixeira; Junqueira, Roberto Gonçalves

    2016-04-15

    The resistant starch (RS) contents in 49 sorghum genotypes and the effects of heat treatment using dry and wet heat on the grain and flour from two sorghum genotypes were investigated. The results showed a wide variation in the RS contents of the genotypes analyzed. The RS mean values were grouped into six distinct groups and ranged from 0.31±0.33 g/100 g to 65.66±5.46 g/100 g sorghum flour on dry basis. Dry heat causes minor losses in the RS content with retentions of up to 97.19±1.92% of this compound, whereas wet heat retained at most 6.98±0.43% of the RS. The SC 59 and (SSN76)FC6608 RED KAFIR BAZINE (ASA N23) cultivars, which have an average RS content of 65.51 g/100 g, were appropriate for human consumption, and the use of dry heat is presented as a better alternative for the preservation of RS in heat-treated grains.

  4. Genetic parameters and selection strategies for soybean genotypes resistant to the stink bug-complex.

    Science.gov (United States)

    de Godoi, Cláudio Roberto Cardoso; Pinheiro, José Baldin

    2009-04-01

    Soybean genotypes resistant to stink bugs are derived from complex breeding processes obtained through indirect selection. The aim of the present work was to estimate genetic parameters for guiding selection strategies towards resistant genotypes, based on those traits associated with responses to pod-attacking stink bugs, such as the grain filling period (GFP), leaf retention (LR), percentage index of pod damage (PIPD) and percentage of spotted seeds (PSS). We assessed the parental lines IAC-100 (resistant) and FT-Estrela (susceptible), the progenies F(2) and F (4) , 30 progenies F (2:3) , 30 progenies BC (1) F (2:3) and 30 progenies BC (2) F (2:3) , besides the cultivars BRS Celeste and MGBR-46 (Conquista). Three field experiments, using randomized complete block design with three replications, were installed in Goiânia-GO, in the 2002/03 season. Each experiment consisted of 36 treatments (6 common and 30 regular). Heritability estimates were: 74.6 and 36.1 (GFP); 51.9 and 19.9 (LR); 49.6 and 49.6 (PIPD) and 55.8 and 20.3 (PSS), in both the broad and narrow senses, respectively. Based on these results, we concluded that the best strategy for obtaining stink bug-resistant genotypes consists of selecting the PIPD trait in early generations (F (3) or F (4) ), followed by selection for the GFP, LR and PSS traits in generations with higher endogamy levels.

  5. Genotypic detection of acyclovir-resistant HSV-1: characterization of 67 ACV-sensitive and 14 ACV-resistant viruses.

    Science.gov (United States)

    Frobert, Emilie; Cortay, Jean-Claude; Ooka, Tadamasa; Najioullah, Fatiha; Thouvenot, Danielle; Lina, Bruno; Morfin, Florence

    2008-07-01

    Infections due to herpes simplex virus (HSV) resistant to acyclovir (ACV) represent an important clinical concern in immunocompromised patients. In order to switch promptly to an appropriate treatment, rapid viral susceptibility assays are required. We developed herein a genotyping analysis focusing on thymidine kinase gene (TK) mutations in order to detect acyclovir-resistant HSV in clinical specimens. A total of 85 HSV-1 positive specimens collected from 69 patients were analyzed. TK gene could be sequenced directly for 81 clinical specimens (95%) and 68 HSV-1 specimens could be characterized as sensitive or resistant by genotyping (84%). Genetic characterization of 67 susceptible HSV-1 specimens revealed 10 polymorphisms never previously described. Genetic characterization of 14 resistant HSV-1 revealed 12 HSV-1 with either TK gene additions/deletions (8 strains) or substitutions (4 strains) and 2 HSV-1 with no mutation in the TK gene. DNA polymerase gene was afterwards explored. With this rapid PCR-based assay, ACV-resistant HSV could be detected directly in clinical specimens within 24 h.

  6. Development and characterization of Brassica juncea – fruticulosa introgression lines exhibiting resistance to mustard aphid (Lipaphis erysimi Kalt

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    Atri Chhaya

    2012-11-01

    Full Text Available Abstract Background Mustard aphid is a major pest of Brassica oilseeds. No source for aphid resistance is presently available in Brassica juncea . A wild crucifer, Brassica fruticulosa is known to be resistant to mustard aphid. An artificially synthesized amphiploid, AD-4 (B. fruticulosa × B. rapa var. brown sarson was developed for use as a bridge species to transfer fruticulosa resistance to B. juncea. Using the selfed backcross we could select a large number of lines with resistance to mustard aphid. This paper reports cytogenetic stability of introgression lines, molecular evidence for alien introgression and their reaction to mustard aphid infestation. Results Majority of introgression lines had expected euploid chromosome number(2n= 36, showed normal meiosis and high pollen grain fertility. Well-distributed and transferable simple-sequence repeats (SSR markers for all the 18 B. juncea chromosomes helped to characterize introgression events. Average proportions of recipient and donor genome in the substitution lines were 49.72 and 35.06%, respectively. Minimum alien parent genome presence (27.29% was observed in the introgression line, Ad3K-280 . Introgressed genotypes also varied for their resistance responses to mustard aphid infestations under artificial release conditions for two continuous seasons. Some of the test genotypes showed consistent resistant reaction. Conclusions B.juncea-fruticulosa introgression set may prove to be a very powerful breeding tool for aphid resistance related QTL/gene discovery and fine mapping of the desired genes/QTLs to facilitate marker assisted transfer of identified gene(s for mustard aphid resistance in the background of commercial mustard genotypes.

  7. High resolution genotyping by restriction enzyme-phased sequencing of advanced backcross lines of rice exhibiting differential cold stress recovery

    Science.gov (United States)

    Advanced backcross rice lines MIb 4853-9 and 6885-2 harbor major seedling cold tolerance QTL qCTS4 and qCTS12 from the temperate japonica M202 in the genetic background of the indica IR50. Previous studies have shown that these lines exhibit the same tolerance, based on visual ratings, under constan...

  8. Robust HCV Genotype 3a Infectious Cell Culture System Permits Identification of Escape Variants With Resistance to Sofosbuvir

    DEFF Research Database (Denmark)

    Ramirez Almeida, Santseharay; Mikkelsen, Lotte S.; Gottwein, Judith M.

    2016-01-01

    barrier to resistance for sofosbuvir, whereas resistance to this DAA can be induced in genotype 3a. We therefore isolated HCV genotype 3a variants with reduced sensitivity to sofosbuvir, with increased fitness and with cross-resistance to other NS5B inhibitors. These findings indicate that sofosbuvir......Background & Aims Direct-acting antivirals (DAAs) effectively eradicate chronic hepatitis C virus (HCV) infection, although HCV genotype 3a is less responsive to these drugs. We aimed to develop genotype 3a infectious cultures and study the effects of inhibitors of NS5A and NS5B and resistance...... with increasing concentrations of sofosbuvir was used to promote selection of HCV-resistant variants. Results We engineered a DBN3a variant with 17 substitutions (DBN3acc) that had replication and propagation kinetics in Huh7.5 cells comparable with prototype J6/JFH1. The adaptive mutations also produced culture...

  9. Grizzly bears exhibit augmented insulin sensitivity while obese prior to a reversible insulin resistance during hibernation.

    Science.gov (United States)

    Nelson, O Lynne; Jansen, Heiko T; Galbreath, Elizabeth; Morgenstern, Kurt; Gehring, Jamie Lauren; Rigano, Kimberly Scott; Lee, Jae; Gong, Jianhua; Shaywitz, Adam J; Vella, Chantal A; Robbins, Charles T; Corbit, Kevin C

    2014-08-01

    The confluence of obesity and diabetes as a worldwide epidemic necessitates the discovery of new therapies. Success in this endeavor requires translatable preclinical studies, which traditionally employ rodent models. As an alternative approach, we explored hibernation where obesity is a natural adaptation to survive months of fasting. Here we report that grizzly bears exhibit seasonal tripartite insulin responsiveness such that obese animals augment insulin sensitivity but only weeks later enter hibernation-specific insulin resistance (IR) and subsequently reinitiate responsiveness upon awakening. Preparation for hibernation is characterized by adiposity coupled to increased insulin sensitivity via modified PTEN/AKT signaling specifically in adipose tissue, suggesting a state of "healthy" obesity analogous to humans with PTEN haploinsufficiency. Collectively, we show that bears reversibly cope with homeostatic perturbations considered detrimental to humans and describe a mechanism whereby IR functions not as a late-stage metabolic adaptation to obesity, but rather a gatekeeper of the fed-fasting transition.

  10. Identification of pyrimethamine- and chloroquine-resistant Plasmodium falciparum in Africa between 1984 and 1998: genotyping of archive blood samples

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    Saito-Nakano Yumiko

    2011-12-01

    Full Text Available Abstract Background Understanding the geographical distribution of drug resistance of Plasmodium falciparum is important for the effective treatment of malaria. Drug resistance has previously been inferred mainly from records of clinical resistance. However, clinical resistance is not always consistent with the parasite's genetic resistance. Thus, molecular identification of the parasite's drug resistance is required. In Africa, clinical resistance to pyrimethamine (Pyr and chloroquine (CQ was evident before 1980 but few studies investigating the genetic resistance to these drugs were conducted before the late 1990s. In this study, genotyping of genes involved in resistance to Pyr and CQ was performed using archive blood samples from Africa between 1984 and 1998. Methods Parasite DNA was extracted from P. falciparum-infected blood smears collected from travellers returning to Japan from Africa between 1984 and 1998. Genotypes of the dihydrofolate reductase gene (dhfr and CQ-resistance transporter gene (pfcrt were determined by polymerase chain reaction amplification and sequencing. Results Genotyping of dhfr and pfcrt was successful in 59 and 80 samples, respectively. One wild-type and seven mutant dhfr genotypes were identified. Three dhfr genotypes lacking the S108N mutation (NRSI, ICSI, IRSI; amino acids at positions 51, 59, 108, and 164 with mutations underlined were highly prevalent before 1994 but reduced after 1995, accompanied by an increase in genotypes with the S108N mutation. The dhfr IRNI genotype was first identified in Nigeria in 1991 in the present samples, and its frequency gradually increased. However, two double mutants (ICNI and NRNI, the latter of which was exclusively found in West Africa, were more frequent than the IRNI genotype. Only two pfcrt genotypes were found, the wild-type and a Southeast Asian type (CVIET; amino acids at positions 72-76 with mutations underlined. The CVIET genotype was already present as early as

  11. Increased transmission of Mycobacterium tuberculosis Beijing genotype strains associated with resistance to streptomycin: a population-based study.

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    Tran N Buu

    Full Text Available BACKGROUND: Studies have shown that the Mycobacterium tuberculosis Beijing genotype is an emerging pathogen that is frequently associated with drug resistance. This suggests that drug resistant Beijing strains have a relatively high transmission fitness compared to other drug-resistant strains. METHODS AND FINDINGS: We studied the relative transmission fitness of the Beijing genotype in relation to anti-tuberculosis drug resistance in a population-based study of smear-positive tuberculosis patients prospectively recruited and studied over a 4-year period in rural Vietnam. Transmission fitness was analyzed by clustering of cases on basis of three DNA typing methods. Of 2531 included patients, 2207 (87% were eligible for analysis of whom 936 (42% were in a DNA fingerprint cluster. The clustering rate varied by genotype with 292/786 (37% for the Beijing genotype, 527/802 (67% for the East-African Indian (EAI genotype, and 117/619 (19% for other genotypes. Clustering was associated with the EAI compared to the Beijing genotype (adjusted odds ratio (OR(adj 3.4: 95% CI 2.8-4.4. Patients infected with streptomycin-resistant strains were less frequently clustered than patients infected with streptomycin-susceptible strains when these were of the EAI genotype (OR(adj 0.6, 95% CI 0.4-0.9, while this pattern was reversed for strains of the Beijing genotype (OR(adj 1.3, 95% CI 1.0-1.8, p for difference 0.002. The strong association between Beijing and MDR-TB (OR(adj 7.2; 95% CI 4.2-12.3 existed only if streptomycin resistance was present. CONCLUSIONS: Beijing genotype strains showed less overall transmissibility than EAI strains, but when comparisons were made within genotypes, Beijing strains showed increased transmission fitness when streptomycin-resistant, while the reverse was observed for EAI strains. The association between MDR-TB and Beijing genotype in this population was strongly dependent on resistance to streptomycin. Streptomycin resistance may

  12. Bulbispermine: A Crinine-Type Amaryllidaceae Alkaloid Exhibiting Cytostatic Activity towards Apoptosis-Resistant Glioma Cells

    Science.gov (United States)

    Luchetti, Giovanni; Johnston, Robert; Mathieu, Véronique; Lefranc, Florence; Hayden, Kathryn; Andolfi, Anna; Lamoral-Theys, Delphine; Reisenauer, Mary R.; Champion, Cody; Pelly, Stephen C.; van Otterlo, Willem A. L.; Magedov, Igor V.; Kiss, Robert; Evidente, Antonio; Rogelj, Snezna; Kornienko, Alexander

    2012-01-01

    The Amaryllidaceae alkaloid bulbispermine was derivatized to produce a small group of synthetic analogues. These, together with bulbispermine’s natural crinine-type congeners, were evaluated in vitro against a panel of cancer cell lines with various levels of resistance to proapoptotic stimuli. Bulbispermine, haemanthamine and haemanthidine showed the most potent antiproliferative activities as determined by the MTT colorimetric assay. Among the synthetic bulbispermine analogues, only the C1,C2-dicarbamate derivative exhibited noteworthy growth inhibitory properties. All active compounds were found not to discriminate between the cancer cell lines based on the apoptosis sensitivity criterion and displayed comparable potencies in both cell types, indicating that apoptosis induction is not the primary mechanism responsible for antiproliferative activity in this series of compounds. It was also found that bulbispermine inhibits the proliferation of glioblastoma cells through cytostatic effects, possibly arising from the rigidification of the actin cytoskeleton. These findings lead us to argue that crinine-type alkaloids are potentially useful drug leads for the treatment of apoptosis resistant cancers and glioblastoma in particular. PMID:22389235

  13. Bulbispermine: a crinine-type Amaryllidaceae alkaloid exhibiting cytostatic activity toward apoptosis-resistant glioma cells.

    Science.gov (United States)

    Luchetti, Giovanni; Johnston, Robert; Mathieu, Véronique; Lefranc, Florence; Hayden, Kathryn; Andolfi, Anna; Lamoral-Theys, Delphine; Reisenauer, Mary R; Champion, Cody; Pelly, Stephen C; van Otterlo, Willem A L; Magedov, Igor V; Kiss, Robert; Evidente, Antonio; Rogelj, Snezna; Kornienko, Alexander

    2012-05-01

    The Amaryllidaceae alkaloid bulbispermine was derivatized to produce a small group of synthetic analogues. These, together with bulbispermine's natural crinine-type congeners, were evaluated in vitro against a panel of cancer cell lines with various levels of resistance to pro-apoptotic stimuli. Bulbispermine, haemanthamine, and haemanthidine showed the most potent antiproliferative activities as determined by the MTT colorimetric assay. Among the synthetic bulbispermine analogues, only the C1,C2-dicarbamate derivative exhibited notable growth inhibitory properties. All active compounds were found not to discriminate between the cancer cell lines based on the apoptosis sensitivity criterion; they displayed similar potencies in both cell types, indicating that the induction of apoptosis is not the primary mechanism responsible for antiproliferative activity in this series of compounds. It was also found that bulbispermine inhibits the proliferation of glioblastoma cells through cytostatic effects, possibly arising from rigidification of the actin cytoskeleton. These findings lead us to argue that crinine-type alkaloids are potentially useful drug leads for the treatment of apoptosis-resistant cancers and glioblastoma in particular.

  14. Using drug exposure for predicting drug resistance - A data-driven genotypic interpretation tool.

    Science.gov (United States)

    Pironti, Alejandro; Pfeifer, Nico; Walter, Hauke; Jensen, Björn-Erik O; Zazzi, Maurizio; Gomes, Perpétua; Kaiser, Rolf; Lengauer, Thomas

    2017-01-01

    Antiretroviral treatment history and past HIV-1 genotypes have been shown to be useful predictors for the success of antiretroviral therapy. However, this information may be unavailable or inaccurate, particularly for patients with multiple treatment lines often attending different clinics. We trained statistical models for predicting drug exposure from current HIV-1 genotype. These models were trained on 63,742 HIV-1 nucleotide sequences derived from patients with known therapeutic history, and on 6,836 genotype-phenotype pairs (GPPs). The mean performance regarding prediction of drug exposure on two test sets was 0.78 and 0.76 (ROC-AUC), respectively. The mean correlation to phenotypic resistance in GPPs was 0.51 (PhenoSense) and 0.46 (Antivirogram). Performance on prediction of therapy-success on two test sets based on genetic susceptibility scores was 0.71 and 0.63 (ROC-AUC), respectively. Compared to geno2pheno[resistance], our novel models display a similar or superior performance. Our models are freely available on the internet via www.geno2pheno.org. They can be used for inferring which drug compounds have previously been used by an HIV-1-infected patient, for predicting drug resistance, and for selecting an optimal antiretroviral therapy. Our data-driven models can be periodically retrained without expert intervention as clinical HIV-1 databases are updated and therefore reduce our dependency on hard-to-obtain GPPs.

  15. Genotyping and serotyping of macrolide and multidrug resistant Streptococcus pneumoniae isolated from carrier children

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    S F Swedan

    2016-01-01

    Full Text Available Aims: Streptococcus pneumoniae, an opportunistic pathogen commonly carried asymptomatically in the nasopharynx of children, is associated with increasing rates of treatment failures due to a worldwide increase in drug resistance. We investigated the carriage of S. pneumoniae in children 5 years or younger, the identity of prevalent serotypes, the rates of resistance to macrolides and other antimicrobial agents and the genotypes responsible for macrolide resistance. Materials and Methods: Nasopharyngeal swabs were collected from 157 children under 5 years for cultural isolation of S. pneumoniae. Antibiogram of isolates  was determined using the disk diffusion test, and the minimal inhibitory concentration to macrolides was determined using the E-test. Isolate serotypes and macrolide resistance genes, erm(B and mef(E, were identified using multiplex polymerase chain reactions. Results: S. pneumoniae was recovered from 33.8% of children; 41.9% among males and 21.9% among females (P = 0.009. The highest carriage rate occurred among age groups 7-12 months and 49-60 months. Most frequent serotypes were 19F, 6A/B, 11A, 19A, 14 and 15B/C.  Resistance to macrolides was 60.4%. Resistance to oxacillin, trimethoprim/sulfamethoxazole and clindamycin was present among 90.6%, 54.7% and 32.1% of isolates, respectively. All isolates were susceptible to chloramphenicol, levofloxacin and vancomycin. Isolates resistant to one or more macrolide drugs were more likely to be multidrug resistant. Resistance to clindamycin or oxacillin coexisted with macrolide resistance. Among the erythromycin-resistant isolates, erm(B, mef(E and erm(B and mef(E genes were present at rates of 43.8%, 37.5% and 6.3%, respectively. Erm(B and mef(E were associated with very high level and moderate-to-high level resistance to macrolides, respectively. Conclusion: A significant proportion of children harboured macrolide and multidrug-resistant S. pneumoniae.

  16. Genotypic and phenotypic nevirapine resistance correlates with virological failure during salvage therapy including abacavir and nevirapine

    DEFF Research Database (Denmark)

    Jørgensen, L B; Katzenstein, T L; Gerstoft, J;

    2000-01-01

    OBJECTIVE: To study the development of resistance during 8 weeks of salvage therapy with abacavir and nevirapine in combination with other reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs). METHODS: Samples obtained at baseline and after 8 weeks of therapy from 16 heavily...... and after 2, 4 and 8 weeks of therapy. RESULTS: The majority of patients was genotypically and phenotypically resistant to lamivudine, abacavir, zidovudine and PIs, whereas 50% of the patients showed resistance to nevirapine at baseline in at least one of the methods used. After 8 weeks of salvage therapy...... higher transient reduction in viral load was observed in patients with nevirapine-sensitive HIV at baseline compared to patients with resistant HIV at baseline. CONCLUSION: The transient effect of salvage therapy including abacavir and nevirapine was due to the effect of nevirapine. The lack of effect...

  17. Helicobacter pylori in Vegetables and Salads: Genotyping and Antimicrobial Resistance Properties

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    Emad Yahaghi

    2014-01-01

    Full Text Available From a clinical and epidemiological perspective, it is important to know which genotypes and antibiotic resistance patterns are present in H. pylori strains isolated from salads and vegetables. Therefore, the present investigation was carried out to find this purpose. Three hundred eighty washed and unwashed vegetable samples and fifty commercial and traditional salad samples were collected from Isfahan, Iran. Samples were cultured and those found positive for H. pylori were analyzed using PCR. Antimicrobial susceptibility testing was performed using disk diffusion method. Seven out of 50 (14% salad and 52 out of 380 (13.68% vegetable samples harbored H. pylori. In addition, leek, lettuce, and cabbage were the most commonly contaminated samples (30%. The most prevalent virulence genes were oipA (86.44% and cagA (57.625. VacA s1a (37.28% and iceA1 (47.45% were the most prevalent genotypes. Forty different genotypic combinations were recognized. S1a/cagA+/iceA1/oipA+ (33.89%, s1a/cagA+/iceA2/oipA (30.50%, and m1a/cagA+/iceA1/oipA+ (28.81% were the most prevalent combined genotypes. Bacterial strains had the highest levels of resistance against metronidazole (77.96%, amoxicillin (67.79%, and ampicillin (61.01%. High similarity in the genotyping pattern of H. pylori among vegetable and salad samples and human specimens suggests that vegetable and salads may be the sources of the bacteria.

  18. ESBL Genotypes in Fluoroquinolone-Resistant and Fluoroquinolone-Susceptible ESBL-Producing Escherichia coli Urinary Isolates in Manitoba

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    Philippe RS Lagacé-Wiens

    2007-01-01

    Full Text Available OBJECTIVE: Extended-spectrum beta-lactamase (ESBL-producing Escherichia coli are increasingly common in nosocomial and community settings. Furthermore, fluoroquinolone (FQ and even multidrug resistance (MDR appear to be associated with certain ESBL genotypes. The purpose of the present study was to determine which ESBL genotypes are associated with FQ and MDR in E coli urinary isolates in Manitoba.

  19. Drug resistant Mycobacterium tuberculosis of the Beijing genotype does not spread in Sweden.

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    Solomon Ghebremichael

    Full Text Available BACKGROUND: Drug resistant (DR and multi-drug resistant (MDR tuberculosis (TB is increasing worldwide. In some parts of the world 10% or more of new TB cases are MDR. The Beijing genotype is a distinct genetic lineage of Mycobacterium tuberculosis, which is distributed worldwide, and has caused large outbreaks of MDR-TB. It has been proposed that certain lineages of M. tuberculosis, such as the Beijing lineage, may have specific adaptive advantages. We have investigated the presence and transmission of DR Beijing strains in the Swedish population. METHODOLOGY/PRINCIPAL FINDINGS: All DR M. tuberculosis complex isolates between 1994 and 2008 were studied. Isolates that were of Beijing genotype were investigated for specific resistance mutations and phylogenetic markers. Seventy (13% of 536 DR strains were of Beijing genotype. The majority of the patients with Beijing strains were foreign born, and their country of origin reflects the countries where the Beijing genotype is most prevalent. Multidrug-resistance was significantly more common in Beijing strains than in non-Beijing strains. There was a correlation between the Beijing genotype and specific resistance mutations in the katG gene, the mabA-inhA-promotor and the rpoB gene. By a combined use of RD deletions, spoligotyping, IS1547, mutT gene polymorphism and Rv3135 gene analysis the Beijing strains could be divided into 11 genomic sublineages. Of the patients with Beijing strains 28 (41% were found in altogether 10 clusters (2-5 per cluster, as defined by RFLP IS6110, while 52% of the patients with non-Beijing strains were in clusters. By 24 loci MIRU-VNTR 31 (45% of the patients with Beijing strains were found in altogether 7 clusters (2-11 per cluster. Contact tracing established possible epidemiological linkage between only two patients with Beijing strains. CONCLUSIONS/SIGNIFICANCE: Although extensive outbreaks with non-Beijing TB strains have occurred in Sweden, Beijing strains have not

  20. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis) Ciferri

    Science.gov (United States)

    Nanda, Satyabrata; Chand, Subodh Kumar; Mandal, Purander; Tripathy, Pradyumna; Joshi, Raj Kumar

    2016-01-01

    Purple blotch, caused by Alternaria porri (Ellis) Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ‘CBT-Ac77’ and cultivar ‘Arka Kalyan’ were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur) in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001). All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India. PMID:27904458

  1. Identification of Novel Source of Resistance and Differential Response of Allium Genotypes to Purple Blotch Pathogen, Alternaria porri (Ellis Ciferri

    Directory of Open Access Journals (Sweden)

    Satyabrata Nanda

    2016-12-01

    Full Text Available Purple blotch, caused by Alternaria porri (Ellis Cifferi, is a serious disease incurring heavy yield losses in the bulb and seed crop of onion and garlic worldwide. There is an immediate need for identification of effective resistance sources for use in host resistance breeding. A total of 43 Allium genotypes were screened for purple blotch resistance under field conditions. Allium cepa accession ‘CBT-Ac77’ and cultivar ‘Arka Kalyan’ were observed to be highly resistant. In vitro inoculation of a selected set of genotypes with A. porri, revealed that 7 days after inoculation was suitable to observe the disease severity. In vitro screening of 43 genotypes for resistance to A. porri revealed two resistant lines. An additional 14 genotypes showed consistent moderate resistance in the field as well as in vitro evaluations. Among the related Allium species, A. schoenoprasum and A. roylei showed the least disease index and can be used for interspecific hybridization with cultivated onion. Differential reaction analysis of three A. porri isolates (Apo-Chiplima, Apn-Nasik, Apg-Guntur in 43 genotypes revealed significant variation among the evaluated Allium species (P = 0.001. All together, the present study suggest that, the newly identified resistance sources can be used as potential donors for ongoing purple blotch resistance breeding program in India.

  2. Performance assessment of the GenoType MTBDRplus test and DNA sequencing in detection of multidrug-resistant Mycobacterium tuberculosis.

    Science.gov (United States)

    Huang, Wei-Lun; Chen, Huang-Yau; Kuo, Yuh-Min; Jou, Ruwen

    2009-08-01

    To facilitate the management of multidrug-resistant (MDR) tuberculosis, two nucleic acid sequence-based methods, the GenoType MTBDRplus test and DNA sequencing, were assessed for the rapid detection of drug-resistant Mycobacterium tuberculosis for the first time in the Asia-Pacific region. The performances of these two assays in detecting the presence of rifampin (rifampicin) (RIF) and isoniazid (INH) resistance-associated mutations in the rpoB, katG, inhA regulatory region, inhA, and oxyR-ahpC genes were compared to that of a conventional agar proportion drug susceptibility test. A total of 242 MDR and 30 pansusceptible M. tuberculosis isolates were evaluated in this study. The sensitivities obtained for RIF-resistant detection by the GenoType MTBDRplus test and by resistance gene sequencing were 95.5% and 97.9%, respectively. The sensitivities for INH resistance detection by the GenoType MTBDRplus test and by resistance gene sequencing were 81.8% and 93.4%, respectively. Together, the sensitivity for MDR tuberculosis detection was 78.5% with the GenoType MTBDRplus test and 91.3% by resistance gene sequencing. The specificity for RIF resistance, INH resistance, and MDR detection was 100% by both methods. The GenoType MTBDRplus test has the advantage of a short turnaround time for drug-resistant M. tuberculosis detection. Overall, the two assays performed equally well in detecting RIF resistance (P = 0.13). However, DNA sequencing demonstrated superior performance in detecting INH resistance (P tuberculosis (P GenoType MTBDRplus test, especially for different geographic areas with genetically diverse M. tuberculosis strains.

  3. Phenotypes and genotypes of macrolide-resistant Streptococcus pneumoniae in Serbia

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    Hadnađev Mirjana

    2014-01-01

    Full Text Available Although macrolides are widely used for treating pneumococcal infections, an increase in macrolide resistance might compromise their use. The objective of this study was to determine the prevalence of macrolide-resistant phenotypes and genotypes in macrolide-resistant S. pneumoniae isolates in Serbia. A total of 228 macrolide-resistant strains isolated during the period of 2009-2012, were analyzed. Macrolide resistance phenotypes were determined by a double disk diffusion test. The presence of macrolide resistance genes was detected by PCR. Antibiotics susceptibilities were tested using the VITEK2 system and E test. Among the examined isolates, the MLSB phenotype which is linked to the presence of the erm(B gene dominated (83.3%, while the mef(A gene which is associated with the M phenotype, was identified in 16.7% isolates. Over 40% of isolates expressed co-resistance to penicillin. A multiple-resistant pattern was found in 36.4% strains, more frequently in children. However, all strains were susceptible to telithromycin, vancomycin, linezolid, fluoroquinolones and rifampicin. [Projekat Ministarstva nauke Republike Srbije, br. 175039

  4. Resistance of tomato genotypes to the greenhouse whitefly Trialeurodes vaporariorum (West.) (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Lucatti, Alejandro F; Alvarez, Adriana E; Machado, Cristina R; Gilardón, Elsa

    2010-01-01

    The greenhouse whitefly, Trialeurodes vaporariorum Westwood, is the most common and abundant whitefly in Argentine horticultural greenhouse crops, especially in tomato (Solanum lycopersicum). Resistance in some wild tomato relatives, such as S. peruvianum, S. habrochaites and S. pennellii to the greenhouse whitefly has been described. The Mi gene confers effective resistance against several species of insects, among them the sweet potato whitefly, Bemisia tabaci Gennadius. Resistance to T. vaporariorum was found in the prebreeding line FCN 93-6-2, derived from a cross between S. lycopersicum cultivar Uco Plata INTA (MiMi) and the wild line FCN 3-5 S. habrochaites. The purpose of this study was to evaluate resistance to T. vaporariorum in tomato genotypes and to study the relationship between this resistance and the presence of the REX-1 marker, which is linked to the Mi gene. In a free-choice assay, the average number of adults per leaf and the number of immatures on the middle and basal plant parts were analyzed. In a no-choice assay, the oviposition rate and adult survival rate were calculated. For all variables analyzed, FCN 3-5 was the most resistant strain. Variations were found in the F2 progeny between the prebreeding line FCN 13-1-6-1 and cv. Uco Plata INTA. Results from the F2 progeny indicate that resistance to T. vaporariorum may be polygenic with transgressive segregation. Whitefly resistance was found to be independent of the REX-1 marker.

  5. Beijing genotype of Mycobacterium tuberculosis is significantly associated with linezolid resistance in multidrug-resistant and extensively drug-resistant tuberculosis in China.

    Science.gov (United States)

    Zhang, Zhijian; Pang, Yu; Wang, Yufeng; Liu, Changting; Zhao, Yanlin

    2014-03-01

    Linezolid (LNZ) is a promising antimicrobial agent for the treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB). To investigate the efficacy of LNZ among MDR-TB and XDR-TB in China, the LNZ susceptibility of 158 MDR-TB isolates from the national drug resistance survey was determined by the minimum inhibitory concentration method. The 158 MDR-TB isolates were also sequenced in the 23S rRNA, rplC and rplD genes conferring LNZ resistance and were typed using spoligotyping to identify the Beijing genotype of Mycobacterium tuberculosis. Overall, the prevalence of LNZ-resistant isolates was 10.8% (17/158) among MDR-TB isolates circulating in China. Beijing genotype was significantly associated with LNZ resistance in MDR-TB and XDR-TB (odds ratio=4.66, 95% confidence interval 1.03-21.16; P=0.033). In addition, a higher frequency of LNZ-resistant isolates was observed among XDR-TB strains (60%) compared with the MDR (5.6%; PMutations in 23S rRNA and rplC were responsible for only 29.4% of LNZ-resistant M. tuberculosis among MDR-TB isolates, and a novel non-synonymous substitution His155Asp in rplC was first identified to be contributing to low-level LNZ resistance (2μg/mL) in M. tuberculosis. The unsatisfactory correlation between mutant genotypes highlights the urgent need to investigate another mechanism for LNZ resistance that has not yet been described.

  6. A randomised trial comparing genotypic and virtual phenotypic interpretation of HIV drug resistance: the CREST study.

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    Hales, Gillian; Birch, Chris; Crowe, Suzanne; Workman, Cassy; Hoy, Jennifer F; Law, Matthew G; Kelleher, Anthony D; Lincoln, Douglas; Emery, Sean

    2006-07-28

    The aim of this study was to compare the efficacy of different HIV drug resistance test reports (genotype and virtual phenotype) in patients who were changing their antiretroviral therapy (ART). Randomised, open-label trial with 48-week followup. The study was conducted in a network of primary healthcare sites in Australia and New Zealand. Patients failing current ART with plasma HIV RNA > 2000 copies/mL who wished to change their current ART were eligible. Subjects were required to be > 18 years of age, previously treated with ART, have no intercurrent illnesses requiring active therapy, and to have provided written informed consent. Eligible subjects were randomly assigned to receive a genotype (group A) or genotype plus virtual phenotype (group B) prior to selection of their new antiretroviral regimen. Patient groups were compared for patterns of ART selection and surrogate outcomes (plasma viral load and CD4 counts) on an intention-to-treat basis over a 48-week period. Three hundred and twenty seven patients completing >or= one month of followup were included in these analyses. Resistance tests were the primary means by which ART regimens were selected (group A: 64%, group B: 62%; p = 0.32). At 48 weeks, there were no significant differences between the groups for mean change from baseline plasma HIV RNA (group A: 0.68 log copies/mL, group B: 0.58 log copies/mL; p = 0.23) and mean change from baseline CD4+ cell count (group A: 37 cells/mm(3), group B: 50 cells/mm(3); p = 0.28). In the absence of clear demonstrated benefits arising from the use of the virtual phenotype interpretation, this study suggests resistance testing using genotyping linked to a reliable interpretive algorithm is adequate for the management of HIV infection.

  7. Pre-existing isoniazid resistance, but not the genotype of Mycobacterium tuberculosis drives rifampicin resistance codon preference in vitro.

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    Indra Bergval

    Full Text Available Both the probability of a mutation occurring and the ability of the mutant to persist will influence the distribution of mutants that arise in a population. We studied the interaction of these factors for the in vitro selection of rifampicin (RIF-resistant mutants of Mycobacterium tuberculosis. We characterised two series of spontaneous RIF-resistant in vitro mutants from isoniazid (INH-sensitive and -resistant laboratory strains and clinical isolates, representing various M. tuberculosis genotypes. The first series were selected from multiple parallel 1 ml cultures and the second from single 10 ml cultures. RIF-resistant mutants were screened by Multiplex Ligation-dependent Probe Amplification (MLPA or by sequencing the rpoB gene. For all strains the mutation rate for RIF resistance was determined with a fluctuation assay. The most striking observation was a shift towards rpoB-S531L (TCG→TTG mutations in a panel of laboratory-generated INH-resistant mutants selected from the 10-ml cultures (p<0.001. All tested strains showed similar mutation rates (1.33×10⁻⁸ to 2.49×10⁻⁷ except one of the laboratory-generated INH mutants with a mutation rate measured at 5.71×10⁻⁷, more than 10 times higher than that of the INH susceptible parental strain (5.46-7.44×10⁻⁸. No significant, systematic difference in the spectrum of rpoB-mutations between strains of different genotypes was observed. The dramatic shift towards rpoB-S531L in our INH-resistant laboratory mutants suggests that the relative fitness of resistant mutants can dramatically impact the distribution of (subsequent mutations that accumulate in a M. tuberculosis population, at least in vitro. We conclude that, against specific genetic backgrounds, certain resistance mutations are particularly likely to spread. Molecular screening for these (combinations of mutations in clinical isolates could rapidly identify these particular pathogenic strains. We therefore recommend that

  8. Pre-existing isoniazid resistance, but not the genotype of Mycobacterium tuberculosis drives rifampicin resistance codon preference in vitro.

    Science.gov (United States)

    Bergval, Indra; Kwok, Brian; Schuitema, Anja; Kremer, Kristin; van Soolingen, Dick; Klatser, Paul; Anthony, Richard

    2012-01-01

    Both the probability of a mutation occurring and the ability of the mutant to persist will influence the distribution of mutants that arise in a population. We studied the interaction of these factors for the in vitro selection of rifampicin (RIF)-resistant mutants of Mycobacterium tuberculosis. We characterised two series of spontaneous RIF-resistant in vitro mutants from isoniazid (INH)-sensitive and -resistant laboratory strains and clinical isolates, representing various M. tuberculosis genotypes. The first series were selected from multiple parallel 1 ml cultures and the second from single 10 ml cultures. RIF-resistant mutants were screened by Multiplex Ligation-dependent Probe Amplification (MLPA) or by sequencing the rpoB gene. For all strains the mutation rate for RIF resistance was determined with a fluctuation assay. The most striking observation was a shift towards rpoB-S531L (TCG→TTG) mutations in a panel of laboratory-generated INH-resistant mutants selected from the 10-ml cultures (pmutation rates (1.33×10⁻⁸ to 2.49×10⁻⁷) except one of the laboratory-generated INH mutants with a mutation rate measured at 5.71×10⁻⁷, more than 10 times higher than that of the INH susceptible parental strain (5.46-7.44×10⁻⁸). No significant, systematic difference in the spectrum of rpoB-mutations between strains of different genotypes was observed. The dramatic shift towards rpoB-S531L in our INH-resistant laboratory mutants suggests that the relative fitness of resistant mutants can dramatically impact the distribution of (subsequent) mutations that accumulate in a M. tuberculosis population, at least in vitro. We conclude that, against specific genetic backgrounds, certain resistance mutations are particularly likely to spread. Molecular screening for these (combinations of) mutations in clinical isolates could rapidly identify these particular pathogenic strains. We therefore recommend that isolates are screened for the distribution of resistance

  9. HIV-1 genotypic resistance profile of patients failing antiretroviral therapy in Paraná, Brazil

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    Paula Virginia Michelon Toledo

    2010-08-01

    Full Text Available Antiretroviral therapy (ART has reduced morbidity and mortality related to human immunodeficiency virus (HIV infection, but in spite of this advance, HIV mutations decrease antiretroviral susceptibility, thus contributing to treatment failure in patients. Genotyping HIV-1 allows the selection of new drugs after initial drug failure. This study evaluated the genotypic profile of HIV-1 isolates from treated (drug-experienced patients in Paraná, Brazil. The prevalence of mutations in reverse transcriptase (RT and protease (PR genes were assessed. We analyzed 467 genotypes of patients with HIV-1 viral loads above 1,000 copies/mL. Mutations at HIV-1 RT and PR genes and previously used ART regimens were recorded. The most prevalent RT mutations were: 184V (68.31%, 215YF (51.6%, 103NS (46%, 41L (39.4%, 67N (38.54%, 210W (23.5%, 190ASE (23.2%, and 181C (17.4%. PR mutations were 90M (33.33%, 82ATFS (29%, 46I (26.8% and 54V (22.2%. The prevalence of mutations was in line with previous national and international reports, except to nonnucleoside analogue reverse transcriptase inhibitors related mutations, which were more prevalent in this study. Previous exposure to antiretroviral drugs was associated with genotypic resistance to specific drugs, leading to treatment failure in HIV patients.

  10. HIV-1 Protease with 20 Mutations Exhibits Extreme Resistance to Clinical Inhibitors through Coordinated Structural Rearrangements

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    Agniswamy, Johnson; Shen, Chen-Hsiang; Aniana, Annie; Sayer, Jane M.; Louis, John M.; Weber, Irene T. (GSU); (NIH)

    2012-06-28

    The escape mutant of HIV-1 protease (PR) containing 20 mutations (PR20) undergoes efficient polyprotein processing even in the presence of clinical protease inhibitors (PIs). PR20 shows >3 orders of magnitude decreased affinity for PIs darunavir (DRV) and saquinavir (SQV) relative to PR. Crystal structures of PR20 crystallized with yttrium, substrate analogue p2-NC, DRV, and SQV reveal three distinct conformations of the flexible flaps and diminished interactions with inhibitors through the combination of multiple mutations. PR20 with yttrium at the active site exhibits widely separated flaps lacking the usual intersubunit contacts seen in other inhibitor-free dimers. Mutations of residues 35-37 in the hinge loop eliminate interactions and perturb the flap conformation. Crystals of PR20/p2-NC contain one uninhibited dimer with one very open flap and one closed flap and a second inhibitor-bound dimer in the closed form showing six fewer hydrogen bonds with the substrate analogue relative to wild-type PR. PR20 complexes with PIs exhibit expanded S2/S2' pockets and fewer PI interactions arising from coordinated effects of mutations throughout the structure, in agreement with the strikingly reduced affinity. In particular, insertion of the large aromatic side chains of L10F and L33F alters intersubunit interactions and widens the PI binding site through a network of hydrophobic contacts. The two very open conformations of PR20 as well as the expanded binding site of the inhibitor-bound closed form suggest possible approaches for modifying inhibitors to target extreme drug-resistant HIV.

  11. Novel Conserved Genotypes Correspond to Antibiotic Resistance Phenotypes of E. coli Clinical Isolates.

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    Michelle C Swick

    Full Text Available Current efforts to understand antibiotic resistance on the whole genome scale tend to focus on known genes even as high throughput sequencing strategies uncover novel mechanisms. To identify genomic variations associated with antibiotic resistance, we employed a modified genome-wide association study; we sequenced genomic DNA from pools of E. coli clinical isolates with similar antibiotic resistance phenotypes using SOLiD technology to uncover single nucleotide polymorphisms (SNPs unanimously conserved in each pool. The multidrug-resistant pools were genotypically similar to SMS-3-5, a previously sequenced multidrug-resistant isolate from a polluted environment. The similarity was evenly spread across the entire genome and not limited to plasmid or pathogenicity island loci. Among the pools of clinical isolates, genomic variation was concentrated adjacent to previously reported inversion and duplication differences between the SMS-3-5 isolate and the drug-susceptible laboratory strain, DH10B. SNPs that result in non-synonymous changes in gyrA (encoding the well-known S83L allele associated with fluoroquinolone resistance, mutM, ligB, and recG were unanimously conserved in every fluoroquinolone-resistant pool. Alleles of the latter three genes are tightly linked among most sequenced E. coli genomes, and had not been implicated in antibiotic resistance previously. The changes in these genes map to amino acid positions in alpha helices that are involved in DNA binding. Plasmid-encoded complementation of null strains with either allelic variant of mutM or ligB resulted in variable responses to ultraviolet light or hydrogen peroxide treatment as markers of induced DNA damage, indicating their importance in DNA metabolism and revealing a potential mechanism for fluoroquinolone resistance. Our approach uncovered evidence that additional DNA binding enzymes may contribute to fluoroquinolone resistance and further implicate environmental bacteria as a

  12. Genotypic and phenotypic detection of macrolide and lincosamide resistance in Streptococcus uberis.

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    Schmitt-Van de Leemput, E; Zadoks, R N

    2007-11-01

    Streptococcus uberis isolates (n = 55) were obtained from milk samples of cases of mild clinical mastitis in 55 dairy cows from 35 herds serviced by one veterinary practice in Mayenne, France. Isolates were tested for macrolide and lincosamide resistance by using phenotypic and genotypic methods. Erythromycin resistance was detected in 12 of the 55 (22%) isolates based on agar disc diffusion testing and MIC measurements, and was encoded by ermB. This gene also conferred phenotypic resistance to pirlimycin based on MIC measurements, but the D-test was needed for detection of the resistance phenotype in the agar disc diffusion test. Isolates with ermB were also highly resistant to the macrolide antibiotic spiramycin. Seventeen of the 55 isolates (31%) were classified as resistant to spiramcyin only and as having intermediate susceptibility to spiramycin based on agar disc diffusion testing and MIC measurements, respectively. The genetic mechanism behind this phenotype and its clinical relevance are unknown. The efflux pump gene mefA was not detected in any of the 55 isolates in this study. Pirlimycin resistance without macrolide resistance was encoded by the lincosamide resistance gene linB in 4 isolates. Based on current guidelines, some linB-positive isolates would be classified as susceptible by using phenotypic tests, and alternative values for the interpretation of the agar disc diffusion test are suggested. We conclude that the agar disc diffusion test is a useful indicator for macrolide and lincosamide resistance of Strep. uberis in veterinary practice, provided that the D-test is used for detection of pirlimycin resistance.

  13. MLST Genotypes and Antibiotic Resistance of Campylobacter spp. Isolated from Poultry in Grenada

    Science.gov (United States)

    Stone, Diana; Davis, Margaret; Baker, Katherine; Besser, Tom; Roopnarine, Rohini; Sharma, Ravindra

    2013-01-01

    This study determined whether multilocus sequence types (MLST) of Campylobacter from poultry in 2 farms in Grenada, West Indies, differed by farm, antimicrobial resistance and farm antibiotic use. Farm A used fluoroquinolones in the water and Farm B used tetracyclines. The E-test was used to determine resistance of isolates to seven antibiotics. PCR of the IpxA gene confirmed species and MLST was used to characterize 38 isolates. All isolates were either C. jejuni or C. coli. Farm antibiotic use directly correlated with antimicrobial resistance of Campylobacter isolates. Almost 80% of the isolates from Farm A were fluoroquinolone resistant and 17.9% of the isolates from Farm B were fluoroquinolone resistant. All Campylobacter isolates from Farm A were tetracycline sensitive, whereas 35.7% of isolates from Farm B were tetracycline resistant. Six previously recognized sequence types (STs) and 2 novel STs were identified. Previously recognized STs were those overwhelmingly reported from poultry and humans globally. Isolates with the same ST did not always have the same antibiotic resistance profile. There was little ST overlap between the farms suggesting that within-farm transmission of Campylobacter genotypes may dominate. MLST typing was useful for tracking Campylobacter spp. among poultry units and can help elucidate Campylobacter host-species population structure and its relevance to human health. PMID:23555097

  14. MLST Genotypes and Antibiotic Resistance of Campylobacter spp. Isolated from Poultry in Grenada

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    Diana Stone

    2013-01-01

    Full Text Available This study determined whether multilocus sequence types (MLST of Campylobacter from poultry in 2 farms in Grenada, West Indies, differed by farm, antimicrobial resistance and farm antibiotic use. Farm A used fluoroquinolones in the water and Farm B used tetracyclines. The E-test was used to determine resistance of isolates to seven antibiotics. PCR of the IpxA gene confirmed species and MLST was used to characterize 38 isolates. All isolates were either C. jejuni or C. coli. Farm antibiotic use directly correlated with antimicrobial resistance of Campylobacter isolates. Almost 80% of the isolates from Farm A were fluoroquinolone resistant and 17.9% of the isolates from Farm B were fluoroquinolone resistant. All Campylobacter isolates from Farm A were tetracycline sensitive, whereas 35.7% of isolates from Farm B were tetracycline resistant. Six previously recognized sequence types (STs and 2 novel STs were identified. Previously recognized STs were those overwhelmingly reported from poultry and humans globally. Isolates with the same ST did not always have the same antibiotic resistance profile. There was little ST overlap between the farms suggesting that within-farm transmission of Campylobacter genotypes may dominate. MLST typing was useful for tracking Campylobacter spp. among poultry units and can help elucidate Campylobacter host-species population structure and its relevance to human health.

  15. Genotyping of two Neisseria gonorrhoeae fluroquinolone-resistant strains in the Brazilian Amazon Region

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    William Antunes Ferreira

    2011-08-01

    Full Text Available We report two ciprofloxacin and ofloxacin-resistant Neisseria gonorrhoeae strains that were isolated from the urethral discharge of male patients at the sexually transmitted diseases outpatient clinic of the Alfredo da Matta Foundation (Manaus, state of Amazonas, Brazil. The gonococci displayed minimal inhibitory concentrations (> 32.00 µg/mL and three mutations in the quinolone resistance-determining region (S91F and D95G in GyrA and S87R in ParC. Both isolates were genotyped using N. gonorrhoeae multi-antigen sequence typing and the analysis showed that the ST225 which represented an emerging widespread multi-resistant clone that has also been associated with reduced susceptibility to ceftriaxone. We recommend continued surveillance of this pathogen to assess the efficacy of anti-gonococcal antibiotics in Brazil.

  16. Selecting black-spot resistant papaya genotypes derived from backcrossing and hybrids.

    Science.gov (United States)

    Poltronieri, T P S; Silveira, S F; Vivas, M; Santa Catarina, R; Cortes, D F M; Azevedo, A O N; Pereira, M G

    2017-02-23

    Papaya crop is important to Brazilian agribusiness. However, the expansion of papaya cultivation in the country is affected by the absence of commercial cultivars presenting good disease resistance. The black-spot caused by the fungus Asperisporium caricae is the most damaging foliar disease affecting Brazilian papaya crops. The use of genetically resistant cultivars is a promising strategy to reduce the dependence of papaya crops on fungicides. A field split-plot experiment was carried out in the municipality of Linhares, Espírito Santo State, and included 20 hybrids derived from the cross between 14 superior lines and four elite genotypes ('SS72/12', 'SEKATI', 'JS/12' and '41/7'), two commercial cultivars ('Golden' and 'Tainung 01'), and the superior line '36/7', which were evaluated for resistance to black-spot in the fruits and leaves. The treatments were arranged in a randomized block design with six repetitions of three plants per plot. The incidence and severity of black spot in the fruits and leaves were evaluated at three different times in the 2015-2016 crop season. Lines 4, 9, 21, and the parent SEKATI were notable for their capacity to reduce disease severity in the leaves and fruits. Lines 1, 2, 9, 16, and 19, and the parents 'SEKATI' and 'SS-72/12' had reduced disease incidence in their fruits. The most resistant hybrids 'SS-72/12 X 4', 'SS-72/12 X 6', 'SEKATI X 1', 'SEKATI X 2', 'SEKATI X 6', 'SEKATI X 9', and 'SEKATI X 20' presented negative heterosis values for improved black-spot resistance. The current study allowed the selection of black-spot resistant genotypes and hybrids, which presented a significantly reduced disease index in the field.

  17. Serotypes, genotypes and antimicrobial resistance patterns of human diarrhoeagenic Escherichia coli isolates circulating in southeastern China.

    Science.gov (United States)

    Chen, Y; Chen, X; Zheng, S; Yu, F; Kong, H; Yang, Q; Cui, D; Chen, N; Lou, B; Li, X; Tian, L; Yang, X; Xie, G; Dong, Y; Qin, Z; Han, D; Wang, Y; Zhang, W; Tang, Y-W; Li, L

    2014-01-01

    Diarrhoeagenic Escherichia coli (DEC) infection is a major health problem in developing countries. The prevalence and characteristics of DEC have not been thoroughly investigated in China. Consecutive faecal specimens from outpatients with acute diarrhoea in nine sentinel hospitals in southeastern China were collected from July 2009 to June 2011. Bacterial and viral pathogens were detected by culture and RT-PCR, respectively. DEC isolates were further classified into five pathotypes using multiplex PCR. The O/H serotypes, sequence types (STs) and antimicrobial susceptibility profiles of the DEC isolates were determined. A total of 2466 faecal specimens were collected, from which 347 (14.1%) DEC isolates were isolated. DEC was the dominant bacterial pathogen detected. The DEC isolates included 217 EAEC, 62 ETEC, 52 EPEC, 14 STEC, one EIEC and one EAEC/ETEC. O45 (6.6%) was the predominant serotype. Genotypic analysis revealed that the major genotype was ST complex 10 (87, 25.6%). Isolates belonging to the serogroups or genotypes of O6, O25, O159, ST48, ST218, ST94 and ST1491 were highly susceptible to the majority of antimicrobials. In contrast, isolates belonging to O45, O15, O1, O169, ST38, ST226, ST69, ST31, ST93, ST394 and ST648 were highly resistant to the majority of antimicrobials. DEC accounted for the majority of bacterial pathogens causing acute diarrhoea in southeastern China, and it is therefore necessary to test for all DEC, not only the EHEC O157:H7. Some serogroups or genotypes of DEC were highly resistant to the majority of antimicrobials. DEC surveillance should be emphasized.

  18. A study of Mycobacterium tuberculosis genotypic diversity & drug resistance mutations in Varanasi, north India

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    Anamika Gupta

    2014-01-01

    Full Text Available Background & objectives: One-fifth of the world′s new tuberculosis (TB cases and two-thirds of cases in the South East Asian region occur in India. Molecular typing of Mycobacterium tuberculosis isolates has greatly facilitated to understand the transmission of TB. This study was aimed to investigate the molecular epidemiology of M. tuberculosis genotypes in Varanasi, north India, and their association with clinical presentation among patients with pulmonary TB. Methods: M. tuberculosis isolates from 104 TB patients attending a tertiary referral hospital of north India were screened for susceptibility to isoniazid (INH, rifampicin (RIF, ethambutol (EMB and streptomycin (STR by proportion method and multiplex-allele-specific-polymerase chain reaction (MAS-PCR. These were genotyped by spoligotyping. The spoligotype patterns were compared with those in the international SITVIT2 spoligotyping database. Results: Eighty three of 104 isolates were distributed in 38 SITs, of which SIT3366 was newly created within the present study. The mass of ongoing transmission with MDR-TB isolates in Varanasi, northern India, was linked to Beijing genotype followed by the CAS1_Delhi lineage. HIV-seropositive patients had a significantly higher proportion of clustered isolates than HIV-seronegative patients and compared with the wild type(wt isolates, the isolates with katG315Thr mutation were considerably more likely to be clustered. Interpretation & conclusions: This study gives an insight into the M. tuberculosis genetic biodiversity in Varanasi, north India, the predominant spoligotypes and their impact on disease transmission. In this region of north India, TB is caused by a wide diversity of spoligotypes with predominance of four genotype lineages: Beijing, CAS, EAI and T. The Beijing genotype was the most frequent single spoligotype and strongly associated with multi drug resistant (MDR-TB isolates. These findings may have important implications for control

  19. Resistência de genótipos de soja ao herbicida glyphosate Resistance of soybean genotypes to glyphosate

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    E Matsuo

    2009-12-01

    Full Text Available Avaliou-se a resistência de dez genótipos de soja (Glycine max ao herbicida glyphosate. Foi adotado o esquema fatorial 10 x 4, no delineamento em blocos casualizados, com quatro repetições. O fator A foi composto por dez genótipos de soja, e o B, por quatro doses de glyphosate. A aplicação do herbicida foi realizada no momento em que as plantas de soja apresentavam a segunda folha trifoliolada completamente desenvolvida. Avaliaramse os caracteres: intoxicação das plantas, número de nós da haste principal, altura das plantas e massa seca das plantas. Na avaliação da intoxicação de plantas, tanto aos quatro dias após a aplicação (DAA do herbicida quanto aos 28 DAA, os genótipos convencionais apresentaram médias superiores estatisticamente em comparação com genótipos resistentes ao glyphosate (RR. Verificou-se que, nas avaliações realizadas ao 0 DAA ou aos 28 DAA sob 0,0 g e.a. ha¹, as respostas dos genótipos foram diferentes em todos os caracteres avaliados, com exceção do número de nós aos 28 DAA. Essas diferenças podem ser atribuídas aos efeitos fisiológicos e ambientais ou a características do próprio material. Nas demais doses, os genótipos RR comportaram-se de maneira desejável em detrimento dos genótipos convencionais. Ao considerar todos os caracteres avaliados, pode-se afirmar que Valiosa RR, BCR945G110, BCR945G114, BCR892G132, BCR892G140, BCR1067G210, BCR1070G244 e M-SOY 8008RR comportaram-se de forma semelhante quanto à resistência ao glyphosate quando submetidos até a dose de 2.160 g e.a. ha-1 .Resistance of ten soybean genotypes (Glycine max to the herbicide glyphosate was evaluated. The randomized block experimental design was used under factorial scheme 10 x 4 and four replicates. Factor A was composed of 10 soybean genotypes and factor B of four glyphosate doses. The herbicide was applied when the second trifoliate leaf of the soybean plants was completely developed. The following characters

  20. Genotyping and drug resistance patterns of M. tuberculosis strains in Pakistan

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    Kanji Akbar

    2008-12-01

    Full Text Available Abstract Background The incidence of tuberculosis in Pakistan is 181/100,000 population. However, information about transmission and geographical prevalence of Mycobacterium tuberculosis strains and their evolutionary genetics as well as drug resistance remains limited. Our objective was to determine the clonal composition, evolutionary genetics and drug resistance of M. tuberculosis isolates from different regions of the country. Methods M. tuberculosis strains isolated (2003–2005 from specimens submitted to the laboratory through collection units nationwide were included. Drug susceptibility was performed and strains were spoligotyped. Results Of 926 M. tuberculosis strains studied, 721(78% were grouped into 59 "shared types", while 205 (22% were identified as "Orphan" spoligotypes. Amongst the predominant genotypes 61% were Central Asian strains (CAS ; including CAS1, CAS sub-families and Orphan Pak clusters, 4% East African-Indian (EAI, 3% Beijing, 2% poorly defined TB strains (T, 2% Haarlem and LAM (0.2. Also TbD1 analysis (M. tuberculosis specific deletion 1 confirmed that CAS1 was of "modern" origin while EAI isolates belonged to "ancestral" strain types. Prevalence of CAS1 clade was significantly higher in Punjab (P Conclusion Our results show variation of prevalent M. tuberculosis strain with greater association of CAS1 with the Punjab province. The fact that the prevalent CAS genotype was not associated with drug resistance is encouraging. It further suggests a more effective treatment and control programme should be successful in reducing the tuberculosis burden in Pakistan.

  1. HCV genotypes are differently prone to the development of resistance to linear and macrocyclic protease inhibitors.

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    Valeria Cento

    Full Text Available BACKGROUND: Because of the extreme genetic variability of hepatitis C virus (HCV, we analyzed whether specific HCV-genotypes are differently prone to develop resistance to linear and macrocyclic protease-inhibitors (PIs. METHODS: The study includes 1568 NS3-protease sequences, isolated from PI-naive patients infected with HCV-genotypes 1a (N = 621, 1b (N = 474, 2 (N = 72, 3 (N = 268, 4 (N = 54 5 (N = 6, and 6 (N = 73. Genetic-barrier was calculated as the sum of nucleotide-transitions (score = 1 and/or nucleotide-transversions (score = 2.5 required for drug-resistance-mutations emergence. Forty-three mutations associated with PIs-resistance were analyzed (36A/M/L/G-41R-43S/V-54A/S/V-55A-Q80K/R/L/H/G-109K-138T-155K/Q/T/I/M/S/G/L-156T/V/G/S-158I-168A/H/T/V/E/I/G/N/Y-170A/T-175L. Structural analyses on NS3-protease and on putative RNA-models have been also performed. RESULTS: Overall, NS3-protease was moderately conserved, with 85/181 (47.0% amino-acids showing 94% HCV-2-4; 175L present in 100% HCV-1a-3-5 and >97% HCV-2-4. Furthermore, HCV-3 specifically showed non-conservative polymorphisms (R123T-D168Q at two drug-interacting positions. Regardless of HCV-genotype, 13 PIs resistance-mutations were associated with low genetic-barrier, requiring only 1 nucleotide-substitution (41R-43S/V-54A-55A-80R-156V/T: score = 1; 54S-138T-156S/G-168E/H: score = 2.5. By contrast, by using HCV-1b as reference genotype, nucleotide-heterogeneity led to a lower genetic-barrier for the development of some drug-resistance-mutations in HCV-1a (36M-155G/I/K/M/S/T-170T, HCV-2 (36M-80K-155G/I/K/S/T-170T, HCV-3 (155G/I/K/M/S/T-170T, HCV-4-6 (155I/S/L, and HCV-5 (80G-155G/I/K/M/S/T. CONCLUSIONS: The high degree of HCV genetic variability makes HCV-genotypes, and even subtypes, differently prone to the development of PIs resistance-mutations. Overall, this can account for different responsiveness of HCV-genotypes to PIs, with

  2. Downy mildew resistance induced by Trichoderma harzianum T39 in susceptible grapevines partially mimics transcriptional changes of resistant genotypes

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    Perazzolli Michele

    2012-11-01

    Full Text Available Abstract Background Downy mildew, caused by Plasmopara viticola, is one of the most severe diseases of grapevine and is commonly controlled by fungicide treatments. The beneficial microorganism Trichoderma harzianum T39 (T39 can induce resistance to downy mildew, although the molecular events associated with this process have not yet been elucidated in grapevine. A next generation RNA sequencing (RNA-Seq approach was used to study global transcriptional changes associated with resistance induced by T39 in Vitis vinifera Pinot Noir leaves. The long-term aim was to develop strategies to optimize the use of this agent for downy mildew control. Results More than 14.8 million paired-end reads were obtained for each biological replicate of T39-treated and control leaf samples collected before and 24 h after P. viticola inoculation. RNA-Seq analysis resulted in the identification of 7,024 differentially expressed genes, highlighting the complex transcriptional reprogramming of grapevine leaves during resistance induction and in response to pathogen inoculation. Our data show that T39 has a dual effect: it directly modulates genes related to the microbial recognition machinery, and it enhances the expression of defence-related processes after pathogen inoculation. Whereas several genes were commonly affected by P. viticola in control and T39-treated plants, opposing modulation of genes related to responses to stress and protein metabolism was found. T39-induced resistance partially inhibited some disease-related processes and specifically activated defence responses after P. viticola inoculation, causing a significant reduction of downy mildew symptoms. Conclusions The global transcriptional analysis revealed that defence processes known to be implicated in the reaction of resistant genotypes to downy mildew were partially activated by T39-induced resistance in susceptible grapevines. Genes identified in this work are an important source of markers

  3. Assessment of resistance to the attack of bean beetle Callosobruchus maculatus (Fabricius in chickpea genotypes on the basis of various parameters during storage

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    Muhammad Sarwar

    2012-07-01

    Full Text Available Chickpea (Cicer arietinum L., is an important pulse food. During storage this commodity is severely attacked bybean beetle Callosobruchus maculatus (Fabricius resulting losses in quantity and nutritional quality. Research studies onrelative resistance of 12 chickpea genotypes to the attack of C. maculatus during storage were carried out. The genotypesmost tolerant to bruchids comprised CH-52/02 and B-8/03, whereas, the most susceptible reactions were apparent inCH-86/02 and CC-117/00. The moderate pest incidence was observed in CH-28/02, CH-4/02, CH-32/02, CH-31/02, CH-9/02,CM-772/03, B-8/02 and CM-628/03 genotypes. The tolerant genotypes exhibited hard and wrinkled seed coat, dark browncolour and small size grain. These characteristics demonstrated a significant harmful effect to pest appearance and graindamage. The vulnerable genotypes had soft and smooth seed coat, white seed colour and bigger grain size that causedvulnerability to C. maculatus. Based on the present investigation, chickpea genotypes CH-52/02 and B-8/03 deserve specialconsideration and may be recommended for relatively longer storage to achieve the goal of long term and sustainable pestmanagement strategies.

  4. Berbamine exhibits potent antitumor effects on imatinib-resistant CML cells in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    Yan-lin WEI; Lei XU; Yun LIANG; Xiao-hua XU; Xiao-ying ZHAO

    2009-01-01

    Aim: The aim of this study was to explore the effects and mechanism of berbamine on imatinib-resistant BCR-ABL-positive human leukemia K562 (K562-r) cells in vitro and in vivo. Methods: Cell viability was measured by MTT assay, and apoptotic morphology changes were detected by fluorescence microscopy. The apoptosis rate was measured by flow cytometric assay, mdr-1 mRNA levels were determined by RT-PCR. Bcl-2 family proteins, cytochrome c( cyt C), poly (ADP-ribose) polymerase (PARP), and P-glycoprotein were detected by Western blot. BALB/c nu/nu mice were injected with K562-r ceils subcutaneously. Tumor-bearing mice were treated intravenously with berbamine.Results: MTT tests revealed that berbamine significantly inhibited K562-r cell proliferation and increased the chemo-sensitivity of Kf62-r cells to imatirtib. The apoptosis rate was significantly increased following treatment with 21.2 μmol/L berbamine; formation of typical apoptotic blebs was apparent, as observed by fluorescence microscopy. Expression levels of mdr-1 mRNA and P-gp protein were high in untreated K562-r cells and significantly down-regulated by berbamine treatment. Berbamine-treated K562-r cells also exhibited down-regulated expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, up-regulated expression of the apoptotic proteins Box and cytoplasmic cyt C, and stimulated proteolytic cleavage of PARP. In addition, berbamine also suppressed the growth of K562-r xenotransplanted tumors in vivo. Conclusion: Berbamine inhibited proliferation of K562-r cells both in vitro and in vivo. Berbamine-induced apoptosis in K562-r cells appeared to occur through a mechanism involving Bcl-2 family proteins, as well as mdr-1 mRNA and P-gp pro- tein. 13erbamine in combination with imatirtib restored the chemo-sensitivity of K562-r cells to imatinib. Our findings sug-gest that berbamine may be useful in treating imatinib-resistant CML patients.

  5. Cold-induced responses in annual bluegrass genotypes with differential resistance to pink snow mold (Microdochium nivale).

    Science.gov (United States)

    Bertrand, Annick; Castonguay, Yves; Azaiez, Aïda; Hsiang, Tom; Dionne, Julie

    2011-01-01

    Greens-type annual bluegrass (Poa annua L.) is susceptible to winter stresses including subfreezing temperatures and pink snow mold (SM). To better understand the mechanisms of SM resistance in annual bluegrass, four SM-resistant and four SM-sensitive genotypes were incubated at low temperature with Microdochium nivale (Fries) Samuels & Hallett, the causal agent of pink snow mold. We assessed the impact of a 6-week incubation period with SM at 2 °C under high humidity (≥ 98%) on the accumulation of cold-induced metabolites and on freezing tolerance. Incubation of annual bluegrass inoculated with SM lead to a major decrease in concentration of cryoprotective sugars such as sucrose and HDP (high degree of polymerization) fructans. Conversely, major amino acids linked to stress resistance such as glutamine and arginine increased in crowns of annual bluegrass in response to SM inoculation. One of the major differences between resistant and sensitive genotypes was found in the concentration of HDP fructans, which remained higher in SM-resistant genotypes throughout the incubation period. HDP fructans were also more abundant in freeze-tolerant genotypes, reinforcing their positive impact on winter survival of annual bluegrass. The identification of genotypes that are resistant to both SM and freezing shows the possibility of being able to improve both traits concomitantly.

  6. Study and evaluation of drought resistance of different genotype maize inbred lines

    Institute of Scientific and Technical Information of China (English)

    Weixing ZHANG; Zhi ZHAO; Guangxiao BAI; Fangjing FU

    2008-01-01

    Using cultivating experiments in fields under drought stress, yields and characteristics in morphology, growth and development of different genotype maize inbred lines were studied systematically. We evaluated and classified the drought resistance of these materials based on the needed indexes, including subordinate func-tion values of drought resistance (SV), drought coefficient (DC) and drought index (DI) of yield by fuzzy function method and cluster analysis. We also analyzed the corre-lations between parameters and tested values of traits. The effective parameters and indexes of comprehensive evalu-ation for drought resistance were selected with principal component analysis. The results showed that under drought stress, the yield of maize inbred lines obviously decreased. The anthesis and silking interval (ASI) was prolonged compared with the control, with a smaller leaf area, thinner stalk, shorter and smaller ears, lengthened barren ear tip, a decline in plant height and ear position, reduced grain number per ear and grain weight, which led to a yield decline. Effects of drought treatment on differ-ent maize inbred lines were significantly different. 79-1E, Jiao51, Su1-1 and 18599 were found to be highly resistant to drought, while 1125 and 5311 performed the worst. DI and SV were significantly correlated with drought resist-ance. Our results indicated that DI, SV, yield and leaf area could be used as parameters and indexes to effectively evaluate the drought resistance of maize. Meanwhile, DC, plant height, ASI, grain number per ear or row, ear length and diameter could be taken as auxiliary para-meters and indexes. An applied scientific method for the comprehensive evaluation of drought resistance was offered in this paper.

  7. Using Genotyping by Sequencing to Map Two Novel Anthracnose Resistance Loci in Sorghum bicolor.

    Science.gov (United States)

    J Felderhoff, Terry; M McIntyre, Lauren; Saballos, Ana; Vermerris, Wilfred

    2016-07-07

    Colletotrichum sublineola is an aggressive fungal pathogen that causes anthracnose in sorghum [Sorghum bicolor (L.) Moench]. The obvious symptoms of anthracnose are leaf blight and stem rot. Sorghum, the fifth most widely grown cereal crop in the world, can be highly susceptible to the disease, most notably in hot and humid environments. In the southeastern United States the acreage of sorghum has been increasing steadily in recent years, spurred by growing interest in producing biofuels, bio-based products, and animal feed. Resistance to anthracnose is, therefore, of paramount importance for successful sorghum production in this region. To identify anthracnose resistance loci present in the highly resistant cultivar 'Bk7', a biparental mapping population of F3:4 and F4:5 sorghum lines was generated by crossing 'Bk7' with the susceptible inbred 'Early Hegari-Sart'. Lines were phenotyped in three environments and in two different years following natural infection. The population was genotyped by sequencing. Following a stringent custom filtering protocol, totals of 5186 and 2759 informative SNP markers were identified in the two populations. Segregation data and association analysis identified resistance loci on chromosomes 7 and 9, with the resistance alleles derived from 'Bk7'. Both loci contain multiple classes of defense-related genes based on sequence similarity and gene ontologies. Genetic analysis following an independent selection experiment of lines derived from a cross between 'Bk7' and sweet sorghum 'Mer81-4' narrowed the resistance locus on chromosome 9 substantially, validating this QTL. As observed in other species, sorghum appears to have regions of clustered resistance genes. Further characterization of these regions will facilitate the development of novel germplasm with resistance to anthracnose and other diseases. Copyright © 2016 Felderhoff et al.

  8. Prevalence, Antimicrobial Resistance, and Genotypic Characterization of Vancomycin-Resistant Enterococci in Meat Preparations.

    Science.gov (United States)

    Guerrero-Ramos, Emilia; Molina-González, Diana; Blanco-Morán, Sonia; Igrejas, Gilberto; Poeta, Patrícia; Alonso-Calleja, Carlos; Capita, Rosa

    2016-05-01

    A total of 160 samples of poultry (80), pork (40), and beef (40) preparations (red sausages, white sausages, hamburgers, meatballs, nuggets, minced meat, escalope, and crepes) were tested in northwestern Spain to determine the prevalence of vancomycin-resistant enterococci (VRE). VRE were detected in 38 (23.8%) samples (37.5% of poultry, 15.0% of pork, and 5.0% of beef samples). One strain per food sample was further characterized. Isolates were identified as Enterococcus faecium (14 strains), E. durans (10), E. hirae (7), E. gallinarum (5), and E. casseliflavus-E. flavescens (2). All strains showed resistance or intermediate susceptibility to three or more antimicrobials of clinical significance, in addition to vancomycin. High rates of resistance or intermediate susceptibility were observed for teicoplanin (81.6% of isolates), chloramphenicol (81.6%), erythromycin (100%), quinupristin-dalfopristin (89.5%), and ciprofloxacin (81.6%). A moderate rate of resistance or intermediate susceptibility emerged for ampicillin (34.2%) and tetracycline (36.8%). Genes encoding antimicrobial resistance and virulence were studied by PCR. The vanA, vanB, vanC-1, and vanC-2/3 genes were identified in 27, 1, 5, and 2 isolates, respectively. Other resistance genes or transposon sequences found were tet(L), tet(M), Tn5397 (tetracycline), erm(A), erm(B) (erythromycin), vat(D), and vat(E) (quinupristin-dalfopristin). Most isolates were free of virulence determinants (agg, hyl, and efaAfm genes were detected in one, one, and five strains, respectively). Strains were classified as not biofilm producers (crystal violet assay; 4 isolates) or weak biofilm producers (34 isolates). Cluster analysis (EcoRI ribotyping) suggested a strong genetic relationship among isolates from different types of meat preparations, animal species, and retail outlets. Meat preparations might play a role in the spread through the food chain of VRE with several resistance and virulence genes.

  9. Antimicrobial resistance and genotypes of staphylococci from bovine milk and the cowshed environment.

    Science.gov (United States)

    Kot, B; Piechota, M; Antos-Bielska, M; Zdunek, E; Wolska, K M; Binek, T; Olszewska, J; Guliński, P; Trafny, E A

    2012-01-01

    Investigation of antimicrobial resistance and genetic relatedness of staphylococci from milk of cows with mastitis and cowshed environment was the aim of this study. Antimicrobial resistance against 14 antimicrobials were determined by using a disc diffusion method. Genetic similarity between the most frequently isolated species was analysed by PFGE (pulsed-field gel electrophoresis). Haemolytic activity, DNase, protease and esterase production was also investigated. Coagulase-negative Staphylococcus species were isolated from 30.8% of milk samples from cows with mastitis. The most frequently isolated species was Staphylococcus xylosus and yield of these organisms was significantly associated with milk of mastitis cows. S. epidermidis was a predominant penicillin-resistant species. High frequency of resistance to lincomycin was observed among isolates of S. sciuri (54.2%) and S. xylosus (25.9%) from cows with mastitis. PFGE (pulsed-field gel electrophoresis) analysis of 29 Staphylococcus aureus isolates showed the presence of 17 PFGE pulsotypes. Isolates of S. sciuri (n = 36) had unique PFGE patterns. Some S. xylosus isolates from milk and milker's hands had the same PFGE pulsotypes, and this observation could indicate that dairyman may be a potential source of the infection. The pulsotype of each of the remaining isolates of S. xylosus suggested that they might have come from common environmental sources; however, these isolates differed in antibiotic resistance pattern or virulence traits. Therefore, knowledge about antibiotic sensitivity pattern and virulence factors of a CNS isolate, besides its genotype, may be informative in tracking the source of the infection.

  10. The genotypic study of Mycobacterium tuberculosis complex resistant to isoniazid: Galicia, Spain (2008-2013).

    Science.gov (United States)

    Pérez Del Molino, M L; Barbeito-Castiñeiras, G; Mejuto, B; Alonso, P; Fernández, A; González-Mediero, G

    2016-11-01

    Incorporation of rapid detection systems to identify mutations in M. tuberculosis complex that confer resistance to isoniazid and rifampicin has potentiated the knowledge of their distribution, given the geographical variability. We performed antibiograms of the 2,993 strains isolated in Galicia, Spain (2008-2013). In the strains resistant to isoniazid, a concentration of 0.4 mg/mL and MTBDRplus Genotype test (Hain Lifescience, Germany) were used. We found that 3.64 % of strains were resistant to isoniazid, while 0.43 % were resistant to isoniazid and rifampicin (multidrug resistant, MDR). The MTBDRplus test showed an overall sensitivity of 72.48 %, with 62.5 % sensitivity for non MDR isoniazid-resistant strains and 100 % sensitivity for MDR strains. The katG gene mutation was detected at codon 315 in 38.53 % of strains. The S315T mutation appeared in 61.54 % of MDR strains and 34.38 % of non-MDR strains. The 28.44 % had mutations in inhA, (93.55 % in C15T), and 38.46 % of MDR strains were mutated. In non-MDR strains, 37.50 % were wild-type, 35.42 % and 27.08 % had mutations in katG and inhA, respectively. The most frequent mutation in rpoβ was S531L (46.15 %). The 38.71 % and 41.9 % of strains with resistance to isoniazid and streptomycin had mutations in katG and inhA, respectively (2 strains with mutations in T8C and T8A). The distribution pattern of resistance among strains with high and low concentrations of isoniazid showed statistically significant differences in relation to the mutation in katG and wild-type. The sensitivity of the Genotype MTBDRplus test for non-MDR strains in our area was at the lower threshold described.

  11. Analysis of hepatitis B virus genotyping and drug resistance gene mutations based on massively parallel sequencing.

    Science.gov (United States)

    Han, Yingxin; Zhang, Yinxin; Mei, Yanhua; Wang, Yuqi; Liu, Tao; Guan, Yanfang; Tan, Deming; Liang, Yu; Yang, Ling; Yi, Xin

    2013-11-01

    Drug resistance to nucleoside analogs is a serious problem worldwide. Both drug resistance gene mutation detection and HBV genotyping are helpful for guiding clinical treatment. Total HBV DNA from 395 patients who were treated with single or multiple drugs including Lamivudine, Adefovir, Entecavir, Telbivudine, Tenofovir and Emtricitabine were sequenced using the HiSeq 2000 sequencing system and validated using the 3730 sequencing system. In addition, a mixed sample of HBV plasmid DNA was used to determine the cutoff value for HiSeq-sequencing, and 52 of the 395 samples were sequenced three times to evaluate the repeatability and stability of this technology. Of the 395 samples sequenced using both HiSeq and 3730 sequencing, the results from 346 were consistent, and the results from 49 were inconsistent. Among the 49 inconsistent results, 13 samples were detected as drug-resistance-positive using HiSeq but negative using 3730, and the other 36 samples showed a higher number of drug-resistance-positive gene mutations using HiSeq 2000 than using 3730. Gene mutations had an apparent frequency of 1% as assessed by the plasmid testing. Therefore, a 1% cutoff value was adopted. Furthermore, the experiment was repeated three times, and the same results were obtained in 49/52 samples using the HiSeq sequencing system. HiSeq sequencing can be used to analyze HBV gene mutations with high sensitivity, high fidelity, high throughput and automation and is a potential method for hepatitis B virus gene mutation detection and genotyping.

  12. Resistance of Asian Cryptococcus neoformans serotype A is confined to few microsatellite genotypes.

    Directory of Open Access Journals (Sweden)

    Weihua Pan

    Full Text Available BACKGROUND: Cryptococcus neoformans is a pathogenic yeast that causes cryptococcosis, a life threatening disease. The prevalence of cryptococcosis in Asia has been rising after the onset of the AIDS epidemic and estimates indicate more than 120 cases per 1,000 HIV-infected individuals per year. Almost all cryptococcal disease cases in both immunocompromised and immunocompetent patients in Asia are caused by C. neoformans var. grubii. Epidemiological studies on C. neoformans in pan-Asia have not been reported. The present work studies the genetic diversity of the fungus by microsatellite typing and susceptibility analysis of approximately 500 isolates from seven Asian countries. METHODOLOGY/PRINCIPAL FINDINGS: Genetic diversity of Asian isolates of C. neoformans was determined using microsatellite analysis with nine microsatellite markers. The analysis revealed eight microsatellite complexes (MCs which showed different distributions among geographically defined populations. A correlation between MCs and HIV-status was observed. Microsatellite complex 2 was mainly associated with isolates from HIV-negative patients, whereas MC8 was associated with those from HIV-positive patients. Most isolates were susceptible to amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole, but 17 (3.4% and 10 (2% were found to be resistant to 5-flucytosine and fluconazole, respectively. Importantly, five Indonesian isolates (approximately 12.5% from all Indonesian isolates investigated and 1% from the total studied isolates were resistant to both antifungals. The majority of 5-flucytosine resistant isolates belonged to MC17. CONCLUSIONS: The findings showed a different distribution of genotypes of C. neoformans var. grubii isolates from various countries in Asia, as well as a correlation of the microsatellite genotypes with the original source of the strains and resistance to 5-flucytosine.

  13. Fluoroquinolone-Resistant Haemophilus parasuis Isolates Exhibit More Putative Virulence Factors than Their Susceptible Counterparts

    OpenAIRE

    Zhang, Qiang; Liu, Jiantao; Yan, Shuxian; Yang, Yujie; Zhang, Anding; Jin, Meilin

    2013-01-01

    The prevalence of 23 putative virulence factors among fluoroquinolone-susceptible and -resistant Haemophilus parasuis isolates was analyzed. Putative hemolysin precursor, fimbrial assembly chaperone, and type I site-specific restriction modification system R subunit genes were more prevalent among fluoroquinolone-resistant H. parasuis isolates than among fluoroquinolone-susceptible H. parasuis isolates. Fluoroquinolone resistance may be associated with an increase in the presence of some viru...

  14. Resistance to antibiotics and genotype characteristics of Salmonella enterica subspecies enterica serovar Mbandaka isolated from poultry

    Directory of Open Access Journals (Sweden)

    Vidanović Dejan

    2008-01-01

    Full Text Available Salmonellas are one of the main zoonotic pathogens whose reservoirs are poultry, cattle and pigs. By means of the food chain salmonellas can be transferred to humans through contaminated food of animal origin. Multiresistant strains Salmonella are particularly dangerous since they can transfer genes of resistance to antibiotics to other microorganisms. Control of salmonellas primarily depends on a good surveillance system and knowledge of the strain types present in the epizootiologic area. In some geographical regions only a few Salmonella serotypes are usually of epidemiological importance. Due to the predomination of some serotypes and fagotypes, when an additional discrimination within serotypes and fagotypes is needed, DNA genotyping is used. In cases when it is necessary to compare the strains which caused the poisoning of patients, with strains isolated from food or animals, a highly discriminatory method is used - pulsed field gel electrophoresis (PFGE. Due to a high degree of discrimination the results of PFGE testing enable decision making with a higher degree of certainty in epizootiologic and epidemiologic research work. The aim of this testing was to determine the antibiotics resistance and genotype characteristics of Salmonella enterica subsp. enterica serovar Mbandaka isolated from poultry from some areas of the territory of Serbia.

  15. Characterization and growth of epitaxial layers of Gs exhibiting high resistivity for ionic implantation

    Science.gov (United States)

    1979-01-01

    Either classical or low temperature epitaxial growth techniques can be used to control the deposition of buffer layers of GaAs on semiconducting substrates and to obtain the resistivity and purity desired. Techniques developed to study, as a function of thickness, the evolution of mobilities by photoHall, and the spectroscopy of shallow and deep centers by cathodoluminescence and current transients reveal one very pure layer of medium resistivity and high mobility, and another "dead layer" of elevated resistivity far from the surface. The highly resistive layer remains pure over several microns, which appears interesting for implantation.

  16. Chronic hepatitis c genotype-4 infection: role of insulin resistance in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    M Hashem Abdel

    2011-11-01

    Full Text Available Abstract Background Hepatitis C virus (HCV is a major cause of chronic hepatitis and hepatocellular carcinoma (HCC and different HCV genotypes show characteristic variations in their pathological properties. Insulin resistance (IR occurs early in HCV infection and may synergize with viral hepatitis in HCC development. Egypt has the highest reported rates of HCV infection (predominantly genotype 4 in the world; this study investigated effects of HCV genotype-4 (HCV-4 on prevalence of insulin resistance in chronic hepatitis C (CHC and HCC in Egyptian patients. Methods Fifty CHC patients, 50 HCC patients and 20 normal subjects were studied. IR was estimated using HOMA-IR index and HCV-4 load determined using real-time polymerase chain reaction. Hepatitis B virus was excluded by enzyme-linked immunosorbent assay. Standard laboratory and histopathological investigations were undertaken to characterize liver function and for grading and staging of CHC; HCC staging was undertaken using intraoperative samples. Results HCC patients showed higher IR frequency but without significant difference from CHC (52% vs 40%, p = 0.23. Multivariate logistic regression analysis showed HOMA-IR index and International Normalization Ratio independently associated with fibrosis in CHC; in HCC, HbA1c, cholesterol and bilirubin were independently associated with fibrosis. Fasting insulin and cholesterol levels were independently associated with obesity in both CHC and HCC groups. Moderate and high viral load was associated with high HOMA-IR in CHC and HCC (p Conclusions IR is induced by HCV-4 irrespective of severity of liver disease. IR starts early in infection and facilitates progression of hepatic fibrosis and HCC development.

  17. Genotypic Resistance of F1 Cotton Hybrids by Inoculation with Different Virulent Isolates of the Fungus Verticillium Dahliae Klebahn

    Institute of Scientific and Technical Information of China (English)

    AMANTURDIEV Alisher; KIM Robert

    2008-01-01

    @@ The plant pathogen Verticilliurn dahliae causes severe cotton losses in Uzbekistan.To create cotton varieties that are resistant to the more virulent races of V.dahliae we wanted to determine genotypic resistance of varieties and lines of cotton to more virulent isolates of different geographic populations of the fungus V.dahliae isolated from different cotton varieties in Uzbekistan and determine the inheritance of wilt resistance with hybrids of the first generation to various isolates of V.dahliae.

  18. [Phenotypic and genotypic characterization of resistance to third-generation cephalosporins in Enterobacter spp].

    Science.gov (United States)

    Bertona, E; Radice, M; Rodríguez, C H; Barberis, C; Vay, C; Famiglietti, A; Gutkind, G

    2005-01-01

    Enterobacter spp. are becoming increasingly frequent nosocomial pathogens with multiple resistance mechanism to beta-lactam antibiotics. We carried out the phenotypic and genotypic characterization of beta-lactamases in 27 Enterobacter spp. (25 Enterobacter cloacae y 2 Enterobacter aerogenes), as well as the ability of different extended spectrum-lactamase (ESBL) screening methods. Resistance to third generation cephalosporins was observed in 15/27 (63%) isolates. Twelve resistant isolates produced high level chromosomal encoded AmpC beta-lactamase; 6 of them were also producers of PER-2. Resistance to third generation cephalosporins in the remaining 3 isolates was due to the presence of ESBLs, PER-2 in 2 cases, and CTX-M-2 in the other. Only CTX-M-2 production was detected with all tested cephalosporins using difusion synergy tests, while cefepime improved ESBLs detection in 7/8 PER-2 producers, 4/8 in the inhibitor approximation test and 7/8 with double disk test using cefepime containing disk with and without clavulanic acid. Dilution method, including cephalosporins with and without the inhibitor detected 1/9 ESBLs producers.

  19. Quantitative Trait Loci from Two Genotypes of Oat (Avena sativa) Conditioning Resistance to Puccinia coronata.

    Science.gov (United States)

    Babiker, Ebrahiem M; Gordon, Tyler C; Jackson, Eric W; Chao, Shiaoman; Harrison, Stephen A; Carson, Martin L; Obert, Don E; Bonman, J Michael

    2015-02-01

    Developing oat cultivars with partial resistance to crown rust would be beneficial and cost-effective for disease management. Two recombinant inbred-line populations were generated by crossing the susceptible cultivar Provena with two partially resistant sources, CDC Boyer and breeding line 94197A1-9-2-2-2-5. A third mapping population was generated by crossing the partially resistant sources to validate the quantitative trait locus (QTL) results. The three populations were evaluated for crown rust severity in the field at Louisiana State University (LSU) in 2009 and 2010 and at the Cereal Disease Laboratory (CDL) in St. Paul, MN, in 2009, 2010, and 2011. An iSelect platform assay containing 5,744 oat single nucleotide polymorphisms was used to genotype the populations. From the 2009 CDL test, linkage analyses revealed two QTLs for partial resistance in the Provena/CDC Boyer population on chromosome 19A. One of the 19A QTLs was also detected in the 2009 LSU test. Another QTL was detected on chromosome 12D in the CDL 2009 test. In the Provena/94197A1-9-2-2-2-5 population, only one QTL was detected, on chromosome 13A, in the CDL 2011 test. The 13A QTL from the Provena/94197A1-9-2-2-2-5 population was validated in the CDC Boyer/94197A1-9-2-2-2-5 population in the CDL 2010 and 2011 tests. Comparative analysis of the significant marker sequences with the rice genome database revealed 15 candidate genes for disease resistance on chromosomes 4 and 6 of rice. These genes could be potential targets for cloning from the two resistant parents.

  20. Clinical characteristics of patients with chronic hepatitis B who developed genotypic resistance to entecavir: Real-life experience.

    Science.gov (United States)

    Kim, Hong Joo; Cho, Yong Kyun; Jeon, Woo Kyu; Kim, Byung Ik

    2017-09-05

    Clinical characteristics of patients with chronic hepatitis B (CHB) who developed genotypic resistance to entecavir (ETV) were compared to those without resistance. Two hundred fifty eight CHB patients who underwent ETV treatment in our institution from July 2007 to May 2013 were included. Eight (3.1%) patients developed genotypic resistance to ETV during the follow-up period. The patterns of genotypic resistance to ETV were as follows: L180M + M204V + S202G (n=3); M204I + V173M (n=1); I169V + V173M (n=1); L180M + M204V + V173L (n=1); L180M + M204V + V173L + M250V (n=1); M204I + V214A + P237H (n=1). The cumulative occurrence rates of genotypic resistance to ETV were not significantly different between CHB patients with prior nucleos(t)tide analogues (NA) exposure (NA experienced, n=56) and NA naïve patients (n=202, P=0.823 by log rank comparison). Older age, higher baseline log10hepatitis B virus-deoxynucleic acid (log10HBV-DNA), higher log10HBV-DNA at 3, 6, 12 and 24 months after baseline, and complete virologic response (CVR, undetectable serum HBV-DNA by polymerase chain reaction 6 months after ETV treatment) were significant contributors to the development of genotypic resistance to ETV. Multivariate analyses showed higher log10HBV-DNA 6 months after baseline and absence of CVR were independent and significant contributors to the development of ETV resistance. Clinical characteristics of patients who developed ETV resistance were higher log10HBV-DNA 6 months after baseline and absence of CVR during the ETV treatment.

  1. Genotypes and oxacillin resistance of Staphylococcus aureus from chicken and chicken meat in Poland.

    Science.gov (United States)

    Krupa, P; Bystroń, J; Bania, J; Podkowik, M; Empel, J; Mroczkowska, A

    2014-12-01

    The genotypes and oxacillin resistance of 263 Staphylococcus aureus isolates cultured from chicken cloacae (n = 138) and chicken meat (n = 125) was analyzed. Fifteen spa types were determined in the studied S. aureus population. Among 5 staphylococcal protein A gene (spa) types detected in S. aureus from chicken, t002, t3478, and t13620 were the most frequent. Staphylococcus aureus isolates from meat were assigned to 14 spa types. Among them, the genotypes t002, t056, t091, t3478, and t13620 were dominant. Except for 4 chicken S. aureus isolates belonging to CC398, the remaining 134 isolates were clustered into multilocus sequence clonal complex (CC) 5. Most of meat-derived isolates were assigned to CC5, CC7, and CC15, and to the newly described spa-CC12954 complex belonging to CC1. Except for t011 (CC398), all other spa types found among chicken isolates were also present in isolates from meat. Four S. aureus isolated from chicken and one from meat were identified as methicillin-resistant S. aureus (MRSA) with oxacillin minimum inhibitory concentrations from 16 to 64 μg/mL. All MRSA were assigned to spa types belonging to ST398, and included 4 animal spa t011 SCCmecV isolates and 1 meat-derived spa t899, SCCmecIV isolate. Borderline oxacillin-resistant S. aureus (BORSA) isolates, shown to grow on plates containing 2 to 3 μg/mL of oxacillin, were found within S. aureus isolates from chicken (3 isolates) and from meat (19 isolates). The spa t091 and t084 dominated among BORSA from chicken meat, whereas t548 and t002 were found within animal BORSA. We report for the first time the presence of MRSA in chicken in Poland. We demonstrate that MRSA CC398 could be found in chicken meat indicating potential of introduction of animal-associated genotypes into the food chain. We also report for the first time the possibility of transmission of BORSA isolates from chicken to meat. ©2014 Poultry Science Association Inc.

  2. The use of dried blood spot specimens for HIV-1 drug resistance genotyping in young children initiating antiretroviral therapy

    Science.gov (United States)

    Salimo, Anna T.; Ledwaba, Johanna; Coovadia, Ashraf; Abrams, Elaine J.; Technau, Karl-Günter; Kuhn, Louise; Morris, Lynn; Hunt, Gillian M.

    2015-01-01

    Paired plasma and dried blood spots (DBS) from 232 South African HIV-infected children initiating antiretroviral therapy (ART) were genotyped for drug resistance mutations, most of who had prior exposure to ART for prevention-of-mother-to-child-transmission. Non-nucleoside reverse transcriptase inhibitor mutations were most commonly detected in both specimen types, particularly Y181C/I and K103N/S. Resistance interpretation concordance was achieved in 97% of pairs with 7 children having mutations detected in DBS only. These results validate the preferential use of DBS specimens for HIVDR genotyping in this patient group. PMID:26192603

  3. Evaluation of the Genotype MTBDR Assay for Rapid Detection of Rifampin and Isoniazid Resistance in Mycobacterium tuberculosis Isolates

    OpenAIRE

    2006-01-01

    A novel PCR-based reverse hybridization method Genotype MTBDR assay (Hain Lifescience GmbH, Nehren, Germany) was evaluated for rapid detection of rifampin (RIF) and isoniazid (INH) resistance in Turkish Mycobacterium tuberculosis isolates. The Genotype MTBDR assay is designed to detect mutations within the 81-bp hotspot region of rpoB and mutations at katG codon 315. A total of 41 RIF-resistant M. tuberculosis isolates with rpoB mutations that were previously tested by the INNO-LiPA Rif.TB ki...

  4. Intermittent hypoxia selects for genotypes and phenotypes that increase survival, invasion, and therapy resistance.

    Directory of Open Access Journals (Sweden)

    Daniel Verduzco

    Full Text Available Hypoxia in tumors correlates with greater risk of metastases, increased invasiveness, and resistance to systemic and radiation therapy. The evolutionary dynamics that links specific adaptations to hypoxia with these observed tumor properties have not been well investigated. While some tumor populations may experience fixed hypoxia, cyclical and stochastic transitions from normoxia to hypoxia are commonly observed in vivo. Although some phenotypic adaptations to this cyclic hypoxia are likely reversible, we hypothesize that some adaptations may become fixed through mutations promoted by hypoxia-induced genomic instability. Here we seek to identify genetic alterations and corresponding stable phenotypes that emerge following cyclic hypoxia. Although these changes may originate as adaptations to this specific environmental stress, their fixation in the tumor genome may result in their observation in tumors from regions of normoxia, a condition known as pseudohypoxia. We exposed several epithelial cell lines to 50 cycles of hypoxia-normoxia, followed by culture in normoxia over a period of several months. Molecular analyses demonstrated permanent changes in expression of several oncogenes and tumor-suppressors, including p53, E-cadherin, and Hif-1α. These changes were associated with increased resistance to multiple cytotoxins, increased survival in hypoxia and increased anchorage-independent growth. These results suggest cycles of hypoxia encountered in early cancers can select for specific and stable genotypic and phenotypic properties that persist even in normoxic conditions, which may promote tumor progression and resistance to therapy.

  5. Phenotypic and genotypic characterization of vancomycin-resistant Enterococcus faecium clinical isolates from two hospitals in Mexico: First detection of VanB phenotype-vanA genotype.

    Science.gov (United States)

    Bocanegra-Ibarias, Paola; Flores-Treviño, Samantha; Camacho-Ortiz, Adrián; Morfin-Otero, Rayo; Villarreal-Treviño, Licet; Llaca-Díaz, Jorge; Martínez-Landeros, Erik Alan; Rodríguez-Noriega, Eduardo; Calzada-Güereca, Andrés; Maldonado-Garza, Héctor Jesús; Garza-González, Elvira

    2016-01-01

    Enterococcus faecium has emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. Our aim was to determine the antimicrobial susceptibility, biofilm production, and clonal relatedness of vancomycin-resistant E. faecium (VREF) clinical isolates from two hospitals in Mexico. Consecutive clinical isolates (n=56) were collected in two tertiary care hospitals in Mexico from 2011 to 2014. VREF isolates were characterized by phenotypic and molecular methods including pulsed-field gel electrophoresis (PFGE). VREF isolates were highly resistant to vancomycin, erythromycin, norfloxacin, high-level streptomycin, and teicoplanin, and showed lower resistance to tetracycline, nitrofurantoin and quinupristin-dalfopristin. None of the isolates were resistant to linezolid. The vanA gene was detected in all isolates. Two VanB phenotype-vanA genotype isolates, highly resistant to vancomycin and susceptible to teicoplanin, were detected. Furthermore, 17.9% of the isolates were classified as biofilm producers, and the espfm gene was found in 98.2% of the isolates. A total of 37 distinct PFGE patterns and 6 clones (25% of the isolates as clone A, 5.4% as clone B, and 3.6% each as clone C, D, E, and F) were detected. Clone A was detected in 5 different wards of the same hospital during 14 months of surveillance. The high resistance to most antimicrobial agents and the moderate cross-transmission of VREF detected accentuates the need for continuous surveillance of E. faecium in the hospital setting. This is also the first reported incidence of the E. faecium VanB phenotype-vanA genotype in the Americas. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  6. The exhibition Namibia-Germany: a shared/divided history. Resistance, violence, memory

    Directory of Open Access Journals (Sweden)

    Clara Himmelheber

    2014-10-01

    Full Text Available The year 2004 was the centenary of the outbreak of a colonial war in former German South West Africa in which thousands of Africans were killed by the colonial power. Although of crucial importance for Namibia, the war had not entered public memory in Germany. The exhibition aimed at presenting colonial history, as well as the contemporary relationships between the two countries, showing a ‘shared’ and a ‘divided’ history. The exhibition created a public debate, which certainly supported the initiative of the German Minister of Economic Co-operation and Development to deliver an apology at the commemoration in August 2004 in Namibia. The article is a post-reflection of one of the co-curators on the exhibition putting it into a larger context and reviewing it concurrently.

  7. Evaluations of melon germplasm reported to exhibit host plant resistance to sweetpotato whitefly

    Science.gov (United States)

    Sweetpotato whitefly (MEAM1 cryptic species of Bemisia tabaci; SPWF) displaced B. tabaci biotype A in 1991 in the lower desert area of southern California and the adjoining areas of Arizona and western Mexico. The search for high-level host plant resistance to this devastating insect has been ongoin...

  8. Good News? Codling Moth Exhibits Negative Cross Resistance Between Guthion and Rimon

    Science.gov (United States)

    The responses of adult codling moth from several field-collected populations and a laboratory-reared colony to residues of Rimon were evaluated in plastic cup adult bioassays. Both fecundity and successful egg hatch varied among populations. Populations of codling moth that exhibited the highest LC5...

  9. Mycobacterium tuberculosis Complex Genotype Diversity and Drug Resistance Profiles in a Pediatric Population in Mexico

    Directory of Open Access Journals (Sweden)

    Mercedes Macías Parra

    2011-01-01

    Full Text Available The aim of this study was to determine the frequency of drug resistance and the clonality of genotype patterns in M. tuberculosis clinical isolates from pediatric patients in Mexico (n=90 patients from 19 states; time period—January 2002 to December 2003. Pulmonary disease was the most frequent clinical manifestation (71%. Children with systemic tuberculosis (TB were significantly younger compared to patients with localized TB infections (mean 7.7±6.2 years versus 15±3.4 years P=0.001. Resistance to any anti-TB drug was detected in 24/90 (26.7% of the isolates; 21/90 (23.3% and 10/90 (11.1% were resistant to Isoniazid and Rifampicin, respectively, and 10/90 (11.1% strains were multidrug-resistant (MDR. Spoligotyping produced a total of 55 different patterns; 12/55 corresponded to clustered isolates (n=47, clustering rate of 52.2%, and 43/55 to unclustered isolates (19 patterns were designated as orphan by the SITVIT2 database. Database comparison led to designation of 36 shared types (SITs; 32 SITs (n=65 isolates matched a preexisting shared type in SITVIT2, whereas 4 SITs (n=6 isolates were newly created. Lineage classification based on principal genetic groups (PGG revealed that 10% of the strains belonged to PGG1 (Bovis and Manu lineages. Among PGG2/3 group, the most predominant clade was the Latin-American and Mediterranean (LAM in 27.8% of isolates, followed by Haarlem and T lineages. The number of single drug-resistant (DR and multidrug-resistant (MDR-TB isolates in this study was similar to previously reported in studies from adult population with risk factors. No association between the spoligotype, age, region, or resistance pattern was observed. However, contrary to a study on M. tuberculosis spoligotyping in Acapulco city that characterized a single cluster of SIT19 corresponding to the EAI2-Manila lineage in 70 (26% of patients, not a single SIT19 isolate was found in our pediatric patient population. Neither did we find any

  10. Collaborative update of a rule-based expert system for HIV-1 genotypic resistance test interpretation.

    Science.gov (United States)

    Paredes, Roger; Tzou, Philip L; van Zyl, Gert; Barrow, Geoff; Camacho, Ricardo; Carmona, Sergio; Grant, Philip M; Gupta, Ravindra K; Hamers, Raph L; Harrigan, P Richard; Jordan, Michael R; Kantor, Rami; Katzenstein, David A; Kuritzkes, Daniel R; Maldarelli, Frank; Otelea, Dan; Wallis, Carole L; Schapiro, Jonathan M; Shafer, Robert W

    2017-01-01

    HIV-1 genotypic resistance test (GRT) interpretation systems (IS) require updates as new studies on HIV-1 drug resistance are published and as treatment guidelines evolve. An expert panel was created to provide recommendations for the update of the Stanford HIV Drug Resistance Database (HIVDB) GRT-IS. The panel was polled on the ARVs to be included in a GRT report, and the drug-resistance interpretations associated with 160 drug-resistance mutation (DRM) pattern-ARV combinations. The DRM pattern-ARV combinations included 52 nucleoside RT inhibitor (NRTI) DRM pattern-ARV combinations (13 patterns x 4 NRTIs), 27 nonnucleoside RT inhibitor (NNRTI) DRM pattern-ARV combinations (9 patterns x 3 NNRTIs), 39 protease inhibitor (PI) DRM pattern-ARV combinations (13 patterns x 3 PIs) and 42 integrase strand transfer inhibitor (INSTI) DRM pattern-ARV combinations (14 patterns x 3 INSTIs). There was universal agreement that a GRT report should include the NRTIs lamivudine, abacavir, zidovudine, emtricitabine, and tenofovir disoproxil fumarate; the NNRTIs efavirenz, etravirine, nevirapine, and rilpivirine; the PIs atazanavir/r, darunavir/r, and lopinavir/r (with "/r" indicating pharmacological boosting with ritonavir or cobicistat); and the INSTIs dolutegravir, elvitegravir, and raltegravir. There was a range of opinion as to whether the NRTIs stavudine and didanosine and the PIs nelfinavir, indinavir/r, saquinavir/r, fosamprenavir/r, and tipranavir/r should be included. The expert panel members provided highly concordant DRM pattern-ARV interpretations with only 6% of NRTI, 6% of NNRTI, 5% of PI, and 3% of INSTI individual expert interpretations differing from the expert panel median by more than one resistance level. The expert panel median differed from the HIVDB 7.0 GRT-IS for 20 (12.5%) of the 160 DRM pattern-ARV combinations including 12 NRTI, two NNRTI, and six INSTI pattern-ARV combinations. Eighteen of these differences were updated in HIVDB 8.1 GRT-IS to reflect the

  11. Mycobacterium tuberculosis Complex Genotype Diversity and Drug Resistance Profiles in a Pediatric Population in Mexico

    Science.gov (United States)

    Macías Parra, Mercedes; Kumate Rodríguez, Jesús; Arredondo García, José Luís; López-Vidal, Yolanda; Castañón-Arreola, Mauricio; Balandrano, Susana; Rastogi, Nalin; Gutiérrez Castrellón, Pedro

    2011-01-01

    The aim of this study was to determine the frequency of drug resistance and the clonality of genotype patterns in M. tuberculosis clinical isolates from pediatric patients in Mexico (n = 90 patients from 19 states; time period—January 2002 to December 2003). Pulmonary disease was the most frequent clinical manifestation (71%). Children with systemic tuberculosis (TB) were significantly younger compared to patients with localized TB infections (mean 7.7 ± 6.2 years versus 15 ± 3.4 years P = 0.001). Resistance to any anti-TB drug was detected in 24/90 (26.7%) of the isolates; 21/90 (23.3%) and 10/90 (11.1%) were resistant to Isoniazid and Rifampicin, respectively, and 10/90 (11.1%) strains were multidrug-resistant (MDR). Spoligotyping produced a total of 55 different patterns; 12/55 corresponded to clustered isolates (n = 47, clustering rate of 52.2%), and 43/55 to unclustered isolates (19 patterns were designated as orphan by the SITVIT2 database). Database comparison led to designation of 36 shared types (SITs); 32 SITs (n = 65 isolates) matched a preexisting shared type in SITVIT2, whereas 4 SITs (n = 6 isolates) were newly created. Lineage classification based on principal genetic groups (PGG) revealed that 10% of the strains belonged to PGG1 (Bovis and Manu lineages). Among PGG2/3 group, the most predominant clade was the Latin-American and Mediterranean (LAM) in 27.8% of isolates, followed by Haarlem and T lineages. The number of single drug-resistant (DR) and multidrug-resistant (MDR-TB) isolates in this study was similar to previously reported in studies from adult population with risk factors. No association between the spoligotype, age, region, or resistance pattern was observed. However, contrary to a study on M. tuberculosis spoligotyping in Acapulco city that characterized a single cluster of SIT19 corresponding to the EAI2-Manila lineage in 70 (26%) of patients, not a single SIT19 isolate was found in our pediatric patient population. Neither did we

  12. Comparative transcriptome profiling of resistant and susceptible rice genotypes in response to the seedborne pathogen Fusarium fujikuroi.

    Science.gov (United States)

    Matić, Slavica; Bagnaresi, Paolo; Biselli, Chiara; Orru', Luigi; Amaral Carneiro, Greice; Siciliano, Ilenia; Valé, Giampiero; Gullino, Maria Lodovica; Spadaro, Davide

    2016-08-11

    Fusarium fujikuroi is the causal agent of bakanae, the most significant seed-borne disease of rice. Molecular mechanisms regulating defence responses of rice towards this fungus are not yet fully known. To identify transcriptional mechanisms underpinning rice resistance, a RNA-seq comparative transcriptome profiling was conducted on infected seedlings of selected rice genotypes at one and three weeks post germination (wpg). Twelve rice genotypes were screened against bakanae disease leading to the identification of Selenio and Dorella as the most resistant and susceptible cultivars, respectively. Transcriptional changes were more appreciable at 3 wpg, suggesting that this infection stage is essential to study the resistance mechanisms: 3,119 DEGs were found in Selenio and 5,095 in Dorella. PR1, germin-like proteins, glycoside hydrolases, MAP kinases, and WRKY transcriptional factors were up-regulated in the resistant genotype upon infection with F. fujikuroi. Up-regulation of chitinases and down-regulation of MAP kinases and WRKY transcriptional factors were observed in the susceptible genotype. Gene ontology (GO) enrichment analyses detected in Selenio GO terms specific to response to F. fujikuroi: 'response to chitin', 'jasmonic acid biosynthetic process', and 'plant-type hypersensitive response', while Dorella activated different mechanisms, such as 'response to salicylic acid stimulus' and 'gibberellin metabolic process', which was in agreement with the production of gibberellin A3 in Dorella plants. RNA-seq profiling was performed for the first time to analyse response of rice to F. fujikuroi infection. Our findings allowed the identification of genes activated in one- and three- week-old rice seedlings of two genotypes infected with F. fujikuroi. Furthermore, we found the pathways involved in bakanae resistance, such as response to chitin, JA-dependent signalling and hypersensitive response. Collectively, this provides important information to elucidate the

  13. Excreting and non-excreting grasses exhibit different salt resistance strategies

    Science.gov (United States)

    Moinuddin, Muhammad; Gulzar, Salman; Ahmed, Muhammad Zaheer; Gul, Bilquees; Koyro, Hans-Werner; Khan, Muhammad Ajmal

    2014-01-01

    The combination of traits that makes a plant successful under saline conditions varies with the type of plant and its interaction with the environmental conditions. Knowledge about the contribution of these traits towards salt resistance in grasses has great potential for improving the salt resistance of conventional crops. We attempted to identify differential adaptive response patterns of salt-excreting versus non-excreting grasses. More specifically, we studied the growth, osmotic, ionic and nutrient (carbon/nitrogen) relations of two salt-excreting (Aeluropus lagopoides and Sporobolus tremulus) and two non-excreting (Paspalum paspalodes and Paspalidium geminatum) perennial C4 grasses under non-saline and saline (0, 200 and 400 mM NaCl) conditions. Growth and relative growth rate decreased under saline conditions in the order P. geminatum > S. tremulus = A. lagopoides > P. paspalodes. The root-to-shoot biomass allocation was unaffected in salt-excreting grasses, increased in P. paspalodes but decreased in P. geminatum. Salt-excreting grasses had a higher shoot/root Na+ ratio than non-excreting grasses. K+, Ca2+ and Mg2+ homoeostasis remained undisturbed among test grasses possibly through improved ion selectivity with rising substrate salinity. Salt-excreting grasses increased leaf succulence, decreased ψs and xylem pressure potential, and accumulated proline and glycinebetaine with increasing salinity. Higher salt resistance of P. paspalodes could be attributed to lower Na+ uptake, higher nitrogen-use efficiency and higher water-use efficiency among the test species. However, P. geminatum was unable to cope with salt-induced physiological drought. More information is required to adequately document the differential strategies of salt resistance in salt-excreting and non-excreting grasses. PMID:24996428

  14. Antiviral therapy against chronic hepatitis B in Brazil: high rates of lamivudine resistance mutations and correlation with HBV genotypes

    Directory of Open Access Journals (Sweden)

    Francisco Campello do Amaral Mello

    2012-05-01

    Full Text Available The effectiveness of antiviral treatments of chronic hepatitis B has been poorly studied in Brazil. Here, hepatitis B virus (HBV DNA positivity, drug resistance mutations and their association with HBV genotypes were evaluated in chronically HBV-infected patients under different drug regimens in Brazil. The study involved 129 patients under interferon or nucleos(tide analogue therapy for a median treatment time of 12 months. One hundred and five (81% of these patients were treated with lamivudine (LAM, either in monotherapy or in combination with newer drugs, such as entecavir (ETV or tenofovir (TDF. High (37.5-100% rates of HBV DNA positivity were observed with all but one drug regimen (LAM + ETV. However, patients that were treated with ETV alone, TDF alone or with LAM combination therapies had a mean viral load that was 3-4 log lower than patients treated with LAM monotherapy. Of the patients treated with LAM, 47% developed resistance mutations. HBV genotypes A (59.1%, D (30.3% and F (9.1% were found. There was no association between the presence of LAM resistance mutations and genotypes, HBeAg status or treatment duration. Nevertheless, the rtM204V mutation was observed more frequently (12/13, 92% in genotype A than in the others (p = 0.023. Six out of nine isolates that contained the rtM204I mutation belonged to genotype D and half of them displayed a single mutation. Genotype D isolates with the rtM204V variant preferentially displayed a triple mutation, while genotype A preferentially displayed a double mutation (p = 0.04.

  15. Association between genotype and drug resistance profiles of Mycobacterium tuberculosis strains circulating in China in a national drug resistance survey

    Science.gov (United States)

    Zhou, Yang; van den Hof, Susan; Wang, Shengfen; Pang, Yu; Zhao, Bing; Xia, Hui; Anthony, Richard; Ou, Xichao; Li, Qiang; Zheng, Yang; Song, Yuanyuan; Zhao, Yanlin; van Soolingen, Dick

    2017-01-01

    We describe the population structure of a representative collection of 3,133 Mycobacterium tuberculosis isolates, collected within the framework of a national resistance survey from 2007 in China. Genotyping data indicate that the epidemic strains in China can be divided into seven major complexes, of which 92% belonged to the East Asian (mainly Beijing strains) or the Euro-American lineage. The epidemic Beijing strains in China are closely related to the Beijing B0/W148 strain earlier described in Russia and a large cluster of these strains has spread national wide. The density of Beijing strains is high in the whole of China (average 70%), but the highest prevalence was found North of the Yellow river. The Euro-American lineage consists of three sublineages (sublineage_1, 2, and 3) and is more prevalent in the South. Beijing lineage showed the highest cluster rate of 48% and a significantly higher level of resistance to rifampicin (14%, p<0.001), ethambutol (9%, p = 0.001), and ofloxacin (5%, p = 0.011). Within the Euro-American Lineage, sublineage_3 revealed the highest cluster rate (28%) and presented a significantly elevated level of resistance to streptomycin (44%, p<0.001). Our findings suggest that standardised treatment in this region may have contributed to the successful spread of certain strains: sublineage_3 in the Euro-American lineage may have thrived when streptomycin was used without rifampicin for treatment, while later under DOTS based treatment, in which rifampicin plays a key role, Beijing lineage appears to be spreading. PMID:28333978

  16. Genotypic variation in morphology and freezing resistance of Eucalyptus globulus seedlings subjected to drought hardening in nursery

    OpenAIRE

    Coopman, Rafael E.; Jara,Jorge C; Escobar,Rene; Luis J Corcuera; Bravo,Leon A

    2010-01-01

    Eucalyptus globulus Labill is one of the most planted species in Chile, because of its fast growth and superior pulp qualities. Nevertheless, the incidence of drought and frost damage immediately after planting is frequent. The purpose of this work was to study the effect of drought hardening on frost resistance and on variations in morphological traits that may increase drought resistance at nursery phase in four genotypes of E. globulus Labill. Drought hardening treatments consisted in indu...

  17. Consequences of Noncompliance for Therapy Efficacy and Emergence of Resistance in Murine Tuberculosis Caused by the Beijing Genotype of Mycobacterium tuberculosis

    OpenAIRE

    2012-01-01

    Despite great effort by health organizations worldwide in fighting tuberculosis (TB), morbidity and mortality are not declining as expected. One of the reasons is related to the evolutionary development of Mycobacterium tuberculosis, in particular the Beijing genotype strains. In a previous study, we showed the association between the Beijing genotype and an increased mutation frequency for rifampin resistance. In this study, we use a Beijing genotype strain and an East-African/Indian genotyp...

  18. Near-isogenic lines of Triticum aestivum with distinct modes of resistance exhibit dissimilar transcriptional regulation during Diuraphis noxia feeding

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    Anna-Maria Botha

    2014-10-01

    Full Text Available Russian wheat aphid (Diuraphis noxia, Kurdjumov feeding on susceptible Triticum aestivum L. leads to leaf rolling, chlorosis and plant death – symptoms not present in resistant lines. Although the effects of several D. noxia (Dn resistance genes are known, none have been isolated or characterized. Wheat varieties expressing different Dn genes exhibit distinct modes of D. noxia resistance, such as antibiosis (Dn1, tolerance (Dn2, and antixenosis (Dn5. However, the mechanism whereby feeding aphids are perceived, and how subsequent transcriptional responses are partitioned into resistance categories, remains unclear. Here we report on downstream events in near-isogenic wheat lines containing different Dn genes after D. noxia biotype SA1 feeding. Transcripts involved in stress, signal transduction, photosynthesis, metabolism and gene regulation were differentially regulated during D. noxia feeding. Expression analyses using RT-qPCR and RNA hybridization, as well as enzyme activity profiling, provide evidence that the timing and intensity of pathways induced are critical in the development of particular modes of resistance. Pathways involved include the generation of kinase signalling cascades that lead to a sustained oxidative burst, and a hypersensitive response that is active during antibiosis. Tolerance is a passive resistance mechanism that acts through repair or de novo synthesis of photosystem proteins. Results further suggest that ethylene-mediated pathways are possibly involved in generating volatile compounds and cell wall fortification during the antixenosic response.

  19. Comparison of genotypic resistance profiles and virological response between patients starting nevirapine and efavirenz in EuroSIDA

    DEFF Research Database (Denmark)

    Bannister, Wendy P; Ruiz, Lidia; Cozzi-Lepri, Alessandro

    2008-01-01

    OBJECTIVE: To compare virological outcome and genotypic resistance profiles in HIV-1-infected patients starting non-nucleoside reverse transcriptase inhibitor (NNRTI)-containing regimens. METHODS: NNRTI-naive patients were included who started treatment with nevirapine (NVP) or efavirenz (EFV) wi...

  20. Drug-resistant gene based genotyping for Acinetobacter baumannii in tracing epidemiological events and for clinical treatment within nosocomial settings

    Institute of Scientific and Technical Information of China (English)

    JIN Hui; XU Xiao-min; MI Zu-huang; MOU Yi; LIU Pei

    2009-01-01

    Background Acinetobacter baumannfi has emerged as an important pathogen related to serious infections and nosocomial outbreaks around the world. However, of the frequently used methods, pulsed-field gel electrophoresis (PFGE) and amplified fragment length polymorphism (AFLP) in Acinetobacter baumannii genotyping lack the direct molecular proof of drug resistance. This study was conducted to establish a typing method based on drug resistant gene identification in contrast to traditional PFGE and AFLP in the period of nosocomial epidemic or outbreak.Methods From January 2005 to October 2005, twenty-seven strains of Acinetobacter species from Intensive Care Units, the Second Affiliated Hospital in Ningbo were isolated, including both epidemic and sporadic events. Susceptibility test, PFGE, AFLP and drug resistance gene typing (DRGT) were carded out to confirm the drug resistance and analyze the genotyping, respectively. PFGE was used as a reference to evaluate the typeability of DRGT and AFLP.Results Twenty-seven strains of Acinetobacter displayed multiple antibiotic resistance and drug resistant genes, and β-lactamase genes were detected in 85.2% strains. The result of DRGT was comparable to PFGE in Acinetobacter strains with different drug resistance though a little difference existed, and even suggested a molecular evolution course of different drug-resistant strains. AFLP showed great polymorphism between strains and had weak ability in distinguishing the drug resistance.Conclusion Compared to AFLP and PFGE, DRGT is useful to analyze localized molecular epidemiology of nosocomial infections and outbreaks, which would benefit clinical diagnosis and therapy.

  1. Genotypes, Virulence Factors and Antimicrobial Resistance Genes of Staphylococcus aureus Isolated in Bovine Subclinical Mastitis from Eastern China

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    Javed Memon§, Yongchun Yang§, Jam Kashifa, Muhammad Yaqoob, Rehana Buriroa, Jamila Soomroa, Wang Liping and Fan Hongjie*

    2013-11-01

    Full Text Available This study was carried out to determine the genotypes, virulence factors and antimicrobial resistance traits of 34 Staphylococcus aureus isolated from subclinical mastitis in Eastern China. Minimal inhibitory concentration (MIC results showed resistance to erythromycin in all isolates. A high frequency of Methicillin resistant S. aureus (MRSA; 29% was observed and these isolates were also highly resistant to penicillin, oxacillin, oxytetracycline and chloramphenicol than methicillin sensitive S. aureus (MSSA isolates. Thirteen pathogenic factors and seven resistance genes including mecA and blaZ gene were checked through PCR. The spaX gene was found in all isolates, whereas cna, spaIg, nuc, clfA, fnbpB, hlA, hlB and seA were present in 35, 79, 85, 59, 35, 85, 71 and 38% isolates, respectively. Nine isolates carried a group of 8 different virulence genes. Moreover, macrolide resistance genes ermB and ermC were present in all isolates. High resistance rate against methicillin was found but no isolate was positive for mecA gene, whereas blaZ and tetK were detected in 82 and 56% isolates, respectively. Genes; fnbpA, seB, seC, seD, dfrK and tetM were not found in any isolate. The statistical association between phenotypic resistance and virulence genes showed, clfA, fnbpB, hlB and seA, were potentially associated with penicillin G, ciprofloxacin, methicillin, chloramphenicol, trimethoprim and oxytetracycline resistance (P≤0.05. REP-PCR based genotyping showed seven distinct genotypes (A-G prevalent in this region. This study reports the presence of multidrug resistant S. aureus in sub-clinical mastitis which were also highly virulent that could be a major obstacle in the treatment of mastitis in this region of China.

  2. Underestimation of the resistance of Mycobacterium tuberculosis to second-line drugs by the new GenoType MTBDRsl test.

    Science.gov (United States)

    Jin, Jialin; Shen, Yaojie; Fan, Xiaoping; Diao, Ni; Wang, Feifei; Wang, Sen; Weng, Xinhua; Zhang, Wenhong

    2013-01-01

    The GenoType MTBDRsl is a new-generation PCR-based line-probe assay for the detection of extensively drug-resistant tuberculosis (XDR-TB). This study evaluated the performance of MTBDRsl in detecting genotypic resistance to ethambutol, kanamycin, and ofloxacin in Mycobacterium tuberculosis (MTB) strains. The drug resistance of 262 unique clinical MTB isolates from China was analyzed with MTBDRsl, traditional TB drug susceptibility testing (DST), and sequencing. Sensitivity of MTBDRsl was 62.4% (93/149; 95% CI = 54.1 to 70.2) for detection of ethambutol resistance, 57.9% (55/95; 95% CI = 47.3 to 68) for kanamycin resistance, and 81% (111/137; 95% CI = 73.4 to 87.2) for ofloxacin resistance; specificity was 76.8% (86/112; 95% CI = 67.9 to 84.2), 98.8% (164/166; 95% CI = 95.7 to 99.9), and 91.1% (113/124; 95% CI = 84.7 to 95.5), respectively. Sequencing suggested that 36.9% (55/149) of ethambutol-resistant strains had no embB306 mutation and that 26.8% (40/149) had embB497 mutation not covered by MTBDRsl. Furthermore, MTBDRsl indicated ethambutol resistance in 23.2% (26/112) of ethambutol-susceptible strains, of which 92.3% (24/26) were confirmed resistant by sequencing. This study demonstrated that genotypic resistance to ethambutol, kanamycin, and ofloxacin in MTB can be quickly determined with the MTBDRsl. As a rapid and convenient genetic method, this assay could function as a supplement to traditional DST. More relevant genetic markers are needed to improve sensitivity.

  3. Genotype-specific mutations in the polymerase gene of hepatitis B virus potentially associated with resistance to oral antiviral therapy.

    Science.gov (United States)

    Mirandola, Silvia; Sebastiani, Giada; Rossi, Cristina; Velo, Emanuela; Erne, Elke Maria; Vario, Alessandro; Tempesta, Diego; Romualdi, Chiara; Campagnolo, Davide; Alberti, Alfredo

    2012-12-01

    The evolution of hepatitis B virus (HBV) and the role of different variants during antiviral therapy may be influenced by HBV genotype. We have therefore analysed substitutions potentially related to nucleos(t)ide analogues (NAs) resistance at 42 positions within RT-region in a cohort of patients with chronic hepatitis B in relation to HBV-genotype. RT mutations analysis was performed by direct sequencing in 200 NAs-naïve patients and in 64 LAM or LAM+ADV experienced patients with NAs resistance, infected mainly by HBV-genotypes D and A. 27 polymorphic-sites were identified among the 42 positions analysed and 64 novel mutations were detected in 23 positions. Genotype-D displayed the highest mutation frequency (6.4%) among all HBV-genotypes analysed. Single or multiple mutations were detected in 80% of naïve patients. Overall, the most frequent single mutations were at residues rt54, rt53 and rt91 which may associate with significantly lower HBV-DNA levels (p=0.001). Comparison with sequencing data of patients failing LMV or LAM+ADV therapy revealed an higher frequency of novel genotype-specific mutations if compared with naïve patients: 3 mutations under LAM monotherapy in HBV-D (rtS85F; rtL91I; rtC256G) and 3 mutations under ADV therapy in HBV-A (rtI53V; rtW153R; rtF221Y). In HBV-D treated patients the dominant resistance mutation was rtL80V (31.4%) and rtM204I (60%) in LAM+ADV group while LAM-treated patients showed a preference of rtM204V (51.9%). Interestingly, none of HBV-A patients had mutation rtM204I under ADV add-on treatment but all of them had the "V" AA substitution. These results suggested that in patients with CHB, HBV-genotype might be relevant in the evolution and development of drug resistance showing also different mutation patterns in the YMDD motif between HBV genotype D and A.

  4. Expression of Cryptogein in tobacco plants exhibits enhanced disease resistance and tolerance to salt stress

    Institute of Scientific and Technical Information of China (English)

    JIANG Donghua; CHEN Xujun; WU Kunlu; GUO Zejian

    2004-01-01

    Cryptogein (Crypt), an elicitin secreted from Phytophthora cryptogea, was used for genetic engineering of biotic and abiotic resistance plants. We generated transgenic tobacco plants harboring a rice phenylalanine ammonia-lyase (PAL) promoter and Crypt fusion gene (PAL::Crypt) or the mutated Crypt (mutation of the lysine at the position 13 to valine) under the control CaMV35S promoter (CaMV35S::CryK13V). T2 progeny of the transgenic plants showed significantly enhanced disease resistance to pathogens of fungal Phytophthora parasitica var nicotiana (Ppn) and Alternaria alternata, and bacterial Pseudomonas syringae pv tabaci. The amount of mRNA accumulation of Crypt and CryK13V was quite low in the transgenic lines analyzed by Northern blot, and was detected by a reverse transcription PCR method. Plants harboring PAL::Crypt construct showed faster and stronger induction of PR-1a gene after Ppn inoculation than that in the wild-type plants. The results suggested that the inducible PAL promoter could rapidly respond to pathogen attack and efficiently suppress the pathogen infection. Furthermore, the enhanced tolerance to salt stress in both of the Crypt and CryK13V expressing tobacco plants was also observed compared with that in the control plants. The constitutive expression of PR and transcription factor genes in the transformants was probably associated with the salt tolerance. The above observations suggested that a cross-talk between biotic and abiotic stresses existed in tobacco plants.

  5. New amino acid changes in drug resistance sites and HBsAg in hepatitis B virus genotype H.

    Science.gov (United States)

    Fernández-Galindo, D A; Sánchez-Ávila, F; Bobadilla-Morales, L; Gómez-Quiróz, P; Bueno-Topete, M; Armendáriz-Borunda, J; Sánchez-Orozco, L V

    2015-06-01

    Long-term treatment with retrotranscriptase (RT) inhibitors eventually leads to the development of drug resistance. Drug-related mutations occur naturally and these can be found in hepatitis B virus (HBV) carriers who have never received antiviral therapy. HBsAg are overlapped with RT domain, thus nucleot(s)ide analogues (NAs) resistance mutations and naturally-occurring mutations can cause amino acid changes in the HBsAg. Twenty-two patients with chronic hepatitis B were enrolled; three of them were previously treated with NAs and 19 were NAs-naïve treated. HBV reverse transcriptase region was sequenced; genotyping and analysis of missense mutations were performed in both RT domain and HBsAg. There was predominance of genotype H. Drug mutations were present in 18.2% of patients. Classical lamivudine resistance mutations (rtM204V/rtL180M) were present in one naïve-treatment patient infected with genotype G. New amino acid changes were identified in drug resistance sites in HBV strains from patients infected with genotype H; rtQ215E was present in two naïve-NAs treatment patients and rtI169M was identified in a patient previously treated with lamivudine. Mutations at sites rt169, rt204, and rt215 resulted in the Y161C, I195M, and C206W mutations at HBsAg. Also, new amino acid changes were identified in B-cell and T-cell epitopes and were more frequent in HBsAg compared to RT domain. In conclusion, new amino acid changes at antiviral resistance sites, B-cell and T-cell epitopes in HBV genotype H were identified in Mexican patients.

  6. Study of Nitrogen terminated doped zigzag GNR FET exhibiting negative differential resistance

    Science.gov (United States)

    Gupta, Santosh Kumar; Jaiswal, Girija Nandan

    2015-10-01

    This paper presents the study of Gallium and Aluminum doped Nitrogen terminated zigzag Graphene Nano Ribbon (GNR) FET with high-k dielectric. The GNR FET structure has been designed and simulated using Quantumwise Atomistix Toolkit software package. The presented GNR FET with n-type (Nitrogen doped) electrodes and p-type (Gallium or Aluminum doped) scattering region are simulated and analyzed using Density Functional Theory combined with NEGF formalism and Device Density of States (DDOS). The device shows a negative differential resistance phenomenon which can be controlled by the gate of the zigzag GNR FET. It is found that doping of Gallium and Aluminum in scattering region provides higher drain current, higher ION/IOFF and IP/IV ratios as compared to that of Boron doped zigzag GNR FET. The potential applications of the device are in logical, high frequency, and memory devices.

  7. Antifungal activity of a new phenolic compound from capitulum of a head rot-resistant sunflower genotype.

    Science.gov (United States)

    Prats, Elena; Galindo, Juan C; Bazzalo, Maria E; León, Alberto; Macías, Francisco A; Rubiales, Diego; Jorrín, Jesús V

    2007-12-01

    In a previous study, we observed that bract and corolla extracts from a Sclerotinia sclerotiorum-resistant sunflower contained high amounts of the known coumarins scopoletin, scopolin, and ayapin. There was a correlation between coumarin concentration and disease resistance. Thin layer chromatography showed higher concentrations of three other compounds in the resistant genotype when compared to the susceptible. A bioassay-directed purification that used column chromatography and HPLC allowed the isolation of a new compound, 3-acetyl-4-acetoxyacetophenone, and known compounds, demethoxyencecalin and 3-acetyl-4-hydroxyacetophenone. Structures were assigned from spectral data, and bioactivities were characterized by in vitro bioassays against S. sclerotiorum. The new compound, 3-acetyl-4-acetoxyacetophenone, had an antifungal activity similar to the coumarin ayapin, previously described as a potent Sclerotinia inhibitor. The speed and simplicity by which these compounds can be detected make them suitable for use in screening procedures that may identify genotypes with valuable levels of resistance. A screening of seven sunflower genotypes in a field experiment showed a correlation between these compounds and resistance to Sclerotinia.

  8. Genotype screening of APLN rs3115757 variant in Egyptian women population reveals an association with obesity and insulin resistance.

    Science.gov (United States)

    Aboouf, Mostafa A; Hamdy, Nadia M; Amin, Ashraf I; El-Mesallamy, Hala O

    2015-07-01

    Apelin is one of adipokines that plays a pivotal role in energy metabolism, insulin sensitivity and vascular integrity. A definite genetic variant of apelin gene (APLN), rs3115757, was recently introduced to potentially influence apelin expression in adipocytes. The aim of our study was to explore the sights of a potential association of this functional variant with obesity traits, insulin resistance indices as well as type 2 diabetes mellitus (T2DM) prevalence. Genotype screening for rs3115757 variant in 151 Egyptian female samples was conducted. Fasting levels of serum insulin and lipid profile, in addition to plasma glucose were measured. Cochran-Armitage trend test was used to decide the risk allele and evaluate the association between the candidate variant and obesity using a case-control design. The homozygous G risk allele carriers showed higher values of body mass index (BMI) and waist circumference (P=0.001,0.02, respectively) as compared to CC or CG genotypes. As for GG genotype carriers, the risk of developing morbid obesity in lean subjects, (BMIresistant to insulin. Significantly after correction for BMI and age effects, GG genotype carriers showed 14% and 41% increment in insulin level and resistance (OR=1.14, 95% CI: 1.06, 1.23, P=0.001), (OR=1.42, 95% CI: 1.19, 1.70, Pobesity disorders and as significant as insulin resistance complications. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Tipranavir-Ritonavir Genotypic Resistance Score in Protease Inhibitor-Experienced Patients▿

    Science.gov (United States)

    Marcelin, Anne-Genevieve; Masquelier, Bernard; Descamps, Diane; Izopet, Jacques; Charpentier, Charlotte; Alloui, Chakib; Bouvier-Alias, Magali; Signori-Schmuck, Anne; Montes, Brigitte; Chaix, Marie-Laure; Amiel, Corinne; Santos, Georges Dos; Ruffault, Annick; Barin, Francis; Peytavin, Gilles; Lavignon, Marc; Flandre, Philippe; Calvez, Vincent

    2008-01-01

    To identify mutations associated with the virological response (VR) to a tipranavir-ritonavir (TPV/r)-based regimen, 143 patients previously treated with protease inhibitor (PI) were studied. VR was defined by a decrease of at least 1 log10 in, or undetectable, human immunodeficiency virus (HIV) RNA at month 3. The effect of each mutation in the protease, considering all variants at a residue as a single variable, on the VR to TPV/r was investigated. Mutations at six residues were associated with a lower VR (E35D/G/K/N, M36I/L/V, Q58E, Q61D/E/G/H/N/R, H69I/K/N/Q/R/Y, and L89I/M/R/T/V), and one mutation was associated with a higher VR (F53L/W/Y). The genotypic score M36I/L/V − F53L/W/Y + Q58E + H69I/K/N/Q/R/Y + L89I/M/R/T/V was selected as providing a strong association with VR. For the seven patients with a genotypic score of −1 (viruses with only mutation at codon 53), the percentage of responders was 100% and the percentages were 79%, 56%, 33%, 21%, and 0% for those with scores of 0, 1, 2, 3, and 4, respectively. The percentage of patients showing a response to TPV/r was lower for patients infected with non-clade B viruses (n = 16, all non-B subtypes considered together) than for those infected with clade B viruses (n = 127) (25% and 59%, respectively; P = 0.015). Most mutations associated with VR to TPV/r had not previously been associated with PI resistance. This is consistent with phenotypic analysis showing that TPV has a unique resistance profile. Mutations at five positions (35, 36, 61, 69, and 89) were observed significantly more frequently in patients infected with a non-B subtype than in those infected with the B subtype, probably explaining the lower VR observed in these patients. PMID:18625773

  10. Transgenic Amorphophallus konjac expressing synthesized acyl-homoserine lactonase (aiiA) gene exhibit enhanced resistance to soft rot disease.

    Science.gov (United States)

    Ban, Huifang; Chai, Xinli; Lin, Yongjun; Zhou, Ying; Peng, Donghai; Zhou, Yi; Zou, Yulan; Yu, Ziniu; Sun, Ming

    2009-12-01

    Amorphophallus konjac is an important economic crop widely used in health products and biomaterials. However, this monocotyledonous plant's production is seriously restricted by soft rot disease. Some Bacillus thuringiensis strains generate an endocellular acyl homoserine lactonase (AiiA), which has inhibitory effect on soft rot pathogen through disrupting the signal molecules (N-acylhomoserine lactones, AHL) of their Quorum Sensing system. The aim of our study is to obtain transgenic A. konjac expressing AiiA protein and exhibiting resistance to soft rot. But till now, there is not any report about exogenous gene transformation in A. konjac. In this research, an Agrobacterium-mediated genetic transformation system was constructed. An aiiA gene was synthesized according to the codon usage in A. konjac. Embryogenic callus was infected with the A. tumefaciens strain EHA105 harboring the plant transformation plasmid pU1301 plus synthesized aiiA gene. After antibiotics screening, 34 plants were obtained. PCR analysis showed that positive amplified fragments were present in 21 out of these 34 lines. Southern blot analysis indicated that aiiA gene had integrated into the genome of A. konjac. Western blotting demonstrated that the target protein of interest was reactive with the antibody against AiiA. Further disease resistance detection revealed that all of the tested transgenic A. konjac lines exhibited high resistance to soft rot bacteria Erwinia carotovora subsp. Carotovora (Ecc) SCG1. The protocol is useful for the quality improvement of A. konjac through genetic transformation.

  11. Algorithmic approach to high-throughput molecular screening for alpha interferon-resistant genotypes in hepatitis C patients.

    Science.gov (United States)

    Sreevatsan, S; Bookout, J B; Ringpis, F M; Pottathil, M R; Marshall, D J; De Arruda, M; Murvine, C; Fors, L; Pottathil, R M; Barathur, R R

    1998-07-01

    This study was designed to analyze the feasibility and validity of using Cleavase Fragment Length Polymorphism (CFLP) analysis as an alternative to DNA sequencing for high-throughput screening of hepatitis C virus (HCV) genotypes in a high-volume molecular pathology laboratory setting. By using a 244-bp amplicon from the 5' untranslated region of the HCV genome, 61 clinical samples received for HCV reverse transcription-PCR (RT-PCR) were genotyped by this method. The genotype frequencies assigned by the CFLP method were 44.3% for type 1a, 26.2% for 1b, 13.1% for type 2b, and 5% type 3a. The results obtained by nucleotide sequence analysis provided 100% concordance with those obtained by CFLP analysis at the major genotype level, with resolvable differences as to subtype designations for five samples. CFLP analysis-derived HCV genotype frequencies also concurred with the national estimates (N. N. Zein et al., Ann. Intern. Med. 125:634-639, 1996). Reanalysis of 42 of these samples in parallel in a different research laboratory reproduced the CFLP fingerprints for 100% of the samples. Similarly, the major subtype designations for 19 samples subjected to different incubation temperature-time conditions were also 100% reproducible. Comparative cost analysis for genotyping of HCV by line probe assay, CFLP analysis, and automated DNA sequencing indicated that the average cost per amplicon was lowest for CFLP analysis, at $20 (direct costs). On the basis of these findings we propose that CFLP analysis is a robust, sensitive, specific, and an economical method for large-scale screening of HCV-infected patients for alpha interferon-resistant HCV genotypes. The paper describes an algorithm that uses as a reflex test the RT-PCR-based qualitative screening of samples for HCV detection and also addresses genotypes that are ambiguous.

  12. Transcriptome Analysis of Cotton (Gossypium hirsutum L. Genotypes That Are Susceptible, Resistant, and Hypersensitive to Reniform Nematode (Rotylenchulus reniformis.

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    Ruijuan Li

    Full Text Available Reniform nematode is a semi-endoparasitic nematode species causing significant yield loss in numerous crops, including cotton (Gossypium hirsutum L.. An RNA-sequencing analysis was conducted to measure transcript abundance in reniform nematode susceptible (DP90 & SG747, resistant (BARBREN-713, and hypersensitive (LONREN-1 genotypes of cotton (Gossypium hirsutum L. with and without reniform nematode infestation. Over 90 million trimmed high quality reads were assembled into 84,711 and 80, 353 transcripts using the G. arboreum and the G. raimondii genomes as references. Many transcripts were significantly differentially expressed between the three different genotypes both prior to and during nematode pathogenesis, including transcripts corresponding to the gene ontology categories of cell wall, hormone metabolism and signaling, redox reactions, secondary metabolism, transcriptional regulation, stress responses, and signaling. Further analysis revealed that a number of these differentially expressed transcripts mapped to the G. raimondii and/or the G. arboreum genomes within 1 megabase of quantitative trait loci that had previously been linked to reniform nematode resistance. Several resistance genes encoding proteins known to be strongly linked to pathogen perception and resistance, including LRR-like and NBS-LRR domain-containing proteins, were among the differentially expressed transcripts mapping near these quantitative trait loci. Further investigation is required to confirm a role for these transcripts in reniform nematode susceptibility, hypersensitivity, and/or resistance. This study presents the first systemic investigation of reniform nematode resistance-associated genes using different genotypes of cotton. The candidate reniform nematode resistance-associated genes identified in this study can serve as the basis for further functional analysis and aid in further development of reniform a nematode resistant cotton germplasm.

  13. Blastocystis Isolate B Exhibits Multiple Modes of Resistance against Antimicrobial Peptide LL-37.

    Science.gov (United States)

    Yason, John Anthony; Ajjampur, Sitara Swarna Rao; Tan, Kevin Shyong Wei

    2016-08-01

    Blastocystis is one of the most common eukaryotic organisms found in humans and many types of animals. Several reports have identified its role in gastrointestinal disorders, although its pathogenicity is yet to be clarified. Blastocystis is transmitted via the fecal-to-oral route and colonizes the large intestines. Epithelial cells lining the intestine secrete antimicrobial peptides (AMPs), including beta-defensins and cathelicidin, as a response to infection. This study explores the effects of host colonic antimicrobial peptides, particularly LL-37, a fragment of cathelicidin, on different Blastocystis subtypes. Blastocystis is composed of several subtypes that have genetic, metabolic, and biological differences. These subtypes also have various outcomes in terms of drug treatment and immune response. In this study, Blastocystis isolates from three different subtypes were found to induce intestinal epithelial cells to secrete LL-37. We also show that among the antimicrobial peptides tested, only LL-37 has broad activity on all the subtypes. LL-37 causes membrane disruption and causes Blastocystis to change shape. Blastocystis subtype 7 (ST7), however, showed relative resistance to LL-37. An isolate, ST7 isolate B (ST7-B), from this subtype releases proteases that can degrade the peptide. It also makes the environment acidic, which causes attenuation of LL-37 activity. The Blastocystis ST7-B isolate was also observed to have a thicker surface coat, which may protect the parasite from direct killing by LL-37. This study determined the effects of LL-37 on different Blastocystis isolates and indicates that AMPs have significant roles in Blastocystis infections. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Trichosporon inkin biofilms produce extracellular proteases and exhibit resistance to antifungals.

    Science.gov (United States)

    de Aguiar Cordeiro, Rossana; Serpa, Rosana; Flávia Uchoa Alexandre, Camila; de Farias Marques, Francisca Jakelyne; Vladia Silva de Melo, Charlline; da Silva Franco, Jônatas; José de Jesus Evangelista, Antonio; Pires de Camargo, Zoilo; Samia Nogueira Brilhante, Raimunda; Fabio Gadelha Rocha, Marcos; Luciano Bezerra Moreira, José; de Jesus Pinheiro Gomes Bandeira, Tereza; Júlio Costa Sidrim, José

    2015-11-01

    The aim of this study was to determine experimental conditions for in vitro biofilm formation of clinical isolates of Trichosporon inkin, an important opportunistic pathogen in immunocompromised patients. Biofilms were formed in microtitre plates in three different media (RPMI, Sabouraud and CLED), with inocula of 104, 105 or 106 cells ml- 1, at pH 5.5 and 7.0, and at 35 and 28 °C, under static and shaking conditions for 72 h. Growth kinetics of biofilms were evaluated at 6, 24, 48 and 72 h. Biofilm milieu analysis were assessed by counting viable cells and quantification of nucleic acids released into biofilm supernatants. Biofilms were also analysed for proteolytic activity and antifungal resistance against amphotericin B, caspofungin, fluconazole, itraconazole and voriconazole. Finally, ultrastructural characterization of biofilms formed in microtitre plates and catheter disks was performed by scanning electron microscopy. Greater biofilm formation was observed with a starter inoculum of 106 cells ml- 1, at pH 7.0 at 35 °C and 80 r.p.m., in both RPMI and Sabouraud media. Growth kinetics showed an increase in both viable cells and biomass with increasing incubation time, with maximum production at 48 h. Biofilms were able to disperse viable cells and nucleic acids into the supernatant throughout the developmental cycle. T. inkin biofilms produced more protease than planktonic cells and showed high tolerance to amphotericin B, caspofungin and azole derivatives. Mature biofilms were formed by different morphotypes, such as blastoconidia, arthroconidia and hyphae, in a strain-specific manner. The present article details the multicellular lifestyle of T. inkin and provides perspectives for further research.

  15. Evaluation of dihydrofolate reductase and dihydropteroate synthetase genotypes that confer resistance to sulphadoxine-pyrimethamine in Plasmodium falciparum in Haiti.

    Science.gov (United States)

    Carter, Tamar E; Warner, Megan; Mulligan, Connie J; Existe, Alexander; Victor, Yves S; Memnon, Gladys; Boncy, Jacques; Oscar, Roland; Fukuda, Mark M; Okech, Bernard A

    2012-08-13

    Malaria caused by Plasmodium falciparum infects roughly 30,000 individuals in Haiti each year. Haiti has used chloroquine (CQ) as a first-line treatment for malaria for many years and as a result there are concerns that malaria parasites may develop resistance to CQ over time. Therefore it is important to prepare for alternative malaria treatment options should CQ resistance develop. In many other malaria-endemic regions, antifolates, particularly pyrimethamine (PYR) and sulphadoxine (SDX) treatment combination (SP), have been used as an alternative when CQ resistance has developed. This study evaluated mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes that confer PYR and SDX resistance, respectively, in P. falciparum to provide baseline data in Haiti. This study is the first comprehensive study to examine PYR and SDX resistance genotypes in P. falciparum in Haiti. DNA was extracted from dried blood spots and genotyped for PYR and SDX resistance mutations in P. falciparum using PCR and DNA sequencing methods. Sixty-one samples were genotyped for PYR resistance in codons 51, 59, 108 and 164 of the dhfr gene and 58 samples were genotyped for SDX resistance codons 436, 437, 540 of the dhps gene in P. falciparum. Thirty-three percent (20/61) of the samples carried a mutation at codon 108 (S108N) of the dhfr gene. No mutations in dhfr at codons 51, 59, 164 were observed in any of the samples. In addition, no mutations were observed in dhps at the three codons (436, 437, 540) examined. No significant difference was observed between samples collected in urban vs rural sites (Welch's T-test p-value = 0.53 and permutations p-value = 0.59). This study has shown the presence of the S108N mutation in P. falciparum that confers low-level PYR resistance in Haiti. However, the absence of SDX resistance mutations suggests that SP resistance may not be present in Haiti. These results have important implications for ongoing discussions on

  16. Evaluation of dihydrofolate reductase and dihydropteroate synthetase genotypes that confer resistance to sulphadoxine-pyrimethamine in Plasmodium falciparum in Haiti

    Directory of Open Access Journals (Sweden)

    Carter Tamar E

    2012-08-01

    Full Text Available Abstract Background Malaria caused by Plasmodium falciparum infects roughly 30,000 individuals in Haiti each year. Haiti has used chloroquine (CQ as a first-line treatment for malaria for many years and as a result there are concerns that malaria parasites may develop resistance to CQ over time. Therefore it is important to prepare for alternative malaria treatment options should CQ resistance develop. In many other malaria-endemic regions, antifolates, particularly pyrimethamine (PYR and sulphadoxine (SDX treatment combination (SP, have been used as an alternative when CQ resistance has developed. This study evaluated mutations in the dihydrofolate reductase (dhfr and dihydropteroate synthetase (dhps genes that confer PYR and SDX resistance, respectively, in P. falciparum to provide baseline data in Haiti. This study is the first comprehensive study to examine PYR and SDX resistance genotypes in P. falciparum in Haiti. Methods DNA was extracted from dried blood spots and genotyped for PYR and SDX resistance mutations in P. falciparum using PCR and DNA sequencing methods. Sixty-one samples were genotyped for PYR resistance in codons 51, 59, 108 and 164 of the dhfr gene and 58 samples were genotyped for SDX resistance codons 436, 437, 540 of the dhps gene in P. falciparum. Results Thirty-three percent (20/61 of the samples carried a mutation at codon 108 (S108N of the dhfr gene. No mutations in dhfr at codons 51, 59, 164 were observed in any of the samples. In addition, no mutations were observed in dhps at the three codons (436, 437, 540 examined. No significant difference was observed between samples collected in urban vs rural sites (Welch’s T-test p-value = 0.53 and permutations p-value = 0.59. Conclusion This study has shown the presence of the S108N mutation in P. falciparum that confers low-level PYR resistance in Haiti. However, the absence of SDX resistance mutations suggests that SP resistance may not be present in Haiti. These

  17. Antiretroviral therapy optimisation without genotype resistance testing: a perspective on treatment history based models.

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    Mattia C F Prosperi

    Full Text Available BACKGROUND: Although genotypic resistance testing (GRT is recommended to guide combination antiretroviral therapy (cART, funding and/or facilities to perform GRT may not be available in low to middle income countries. Since treatment history (TH impacts response to subsequent therapy, we investigated a set of statistical learning models to optimise cART in the absence of GRT information. METHODS AND FINDINGS: The EuResist database was used to extract 8-week and 24-week treatment change episodes (TCE with GRT and additional clinical, demographic and TH information. Random Forest (RF classification was used to predict 8- and 24-week success, defined as undetectable HIV-1 RNA, comparing nested models including (i GRT+TH and (ii TH without GRT, using multiple cross-validation and area under the receiver operating characteristic curve (AUC. Virological success was achieved in 68.2% and 68.0% of TCE at 8- and 24-weeks (n = 2,831 and 2,579, respectively. RF (i and (ii showed comparable performances, with an average (st.dev. AUC 0.77 (0.031 vs. 0.757 (0.035 at 8-weeks, 0.834 (0.027 vs. 0.821 (0.025 at 24-weeks. Sensitivity analyses, carried out on a data subset that included antiretroviral regimens commonly used in low to middle income countries, confirmed our findings. Training on subtype B and validation on non-B isolates resulted in a decline of performance for models (i and (ii. CONCLUSIONS: Treatment history-based RF prediction models are comparable to GRT-based for classification of virological outcome. These results may be relevant for therapy optimisation in areas where availability of GRT is limited. Further investigations are required in order to account for different demographics, subtypes and different therapy switching strategies.

  18. Fabrication and characterization of a micromachined swirl-shaped ionic polymer metal composite actuator with electrodes exhibiting asymmetric resistance.

    Science.gov (United States)

    Feng, Guo-Hua; Liu, Kim-Min

    2014-05-12

    This paper presents a swirl-shaped microfeatured ionic polymer-metal composite (IPMC) actuator. A novel micromachining process was developed to fabricate an array of IPMC actuators on a glass substrate and to ensure that no shortcircuits occur between the electrodes of the actuator. We demonstrated a microfluidic scheme in which surface tension was used to construct swirl-shaped planar IPMC devices of microfeature size and investigated the flow velocity of Nafion solutions, which formed the backbone polymer of the actuator, within the microchannel. The unique fabrication process yielded top and bottom electrodes that exhibited asymmetric surface resistance. A tool for measuring surface resistance was developed and used to characterize the resistances of the electrodes for the fabricated IPMC device. The actuator, which featured asymmetric electrode resistance, caused a nonzero-bias current when the device was driven using a zero-bias square wave, and we propose a circuit model to describe this phenomenon. Moreover, we discovered and characterized a bending and rotating motion when the IPMC actuator was driven using a square wave. We observed a strain rate of 14.6% and a displacement of 700 μm in the direction perpendicular to the electrode surfaces during 4.5-V actuation.

  19. Perovskite-type metal oxides exhibiting negligible grain boundary resistance to total electrical conductivity.

    Science.gov (United States)

    Pannu, Tania; Pannu, Kanwar Gulsher Singh; Thangadurai, Venkataraman

    2011-01-17

    In this paper, we report the synthesis, structure and electrical properties of the perovskite-type AZn0.33+xNb0.67-xO3-δ (A = Sr or Ba; 0 ≤ x ≤ 0.08). The investigated compounds were prepared by employing the solid-state (ceramic) reaction using alkaline nitrates, zinc oxide, and niobium oxide at elevated temperatures in air. Powder X-ray diffraction (PXRD) showed the formation of disordered Zn and Nb at the B-sites of space group Pm3̅m with cubic structure and a lattice constant comparable to that of the literature. The AC impedance study showed mainly bulk contribution to the total electrical conductivity over the investigated frequency range of 0.01 Hz to 1 MHz in all the investigated atmospheres even at low temperatures, which is significantly different from that of the well-known perovskite-type B-site ordered BaCa0.33+xNb0.67-xO3-δ and the disordered acceptor-doped BaCeO3. The bulk dielectric constant determined at 500 and 700 °C in air was found to be in the range of 35-100. In air, the isothermal bulk dielectric constant seems to increase with an increasing Zn content, and a similar trend was observed for total electrical conductivity. In dry and wet H2, the electrical conductivity decreases with an increasing Zn content in AZn0.33+xNb0.67-xO3-δ, and the x = 0 member of the Ba compound exhibits the highest total conductivity of 7.2 × 10(-3) S cm(-1) in dry H2 at 800 °C. Both Sr and Ba compounds were found to be stable against the reaction with pure CO2 at 700 °C and H2O at 100 °C for a long period of time. SrZn0.33+xNb0.67-xO3-δ was found to be stable in 30 ppm H2S at 800 °C, while the corresponding Ba compound formed reaction products such as BaS (JCPDS Card 01-0757), BaS2 (JCPDS Card 21-0087), and BaS3 (JCPDS Card 03-0824).

  20. Analysis of resistance to Yam mosaic virus, genus Potyvirus in white guinea yam (Dioscorea rotundata Poir. genotypes

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    Babajide Odu O.

    2011-01-01

    Full Text Available Resistance to Yam mosaic virus (YMV, genus Potyvirus was studied in 10 populations of selected white Guinea yam (Dioscorea rotundata. Plants of resistant genotypes: TDr 35, TDr 1621, TDr 93-1, TDr 93-32, TDr 95-107, TDr 93-23, and susceptible ones: TDr 87/00211, TDr 87/00571 and TDr 95-127 were screened for their reaction to the pathogen by symptom severity scoring scale of 1-5, and by quantifying virus multiplication by triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA. Controlled crosses were made among the genotypes within and between the groups according to reactions to the pathogen. The resultant F1 progenies were evaluated for the infection by disease symptom development and by TAS ELISA to detect a symptomless infection in an insect-proof screenhouse for the assessment of inheritance of resistance to YMV. A genetic analysis of the reactions of progenies derived from the D. rotundata genotypes to inoculation with YMV strongly suggests that resistance to the virus is a dominantly inherited trait. Segregation ratios obtained from the families indicate that at least two dominant genes are involved.

  1. Pooled deep sequencing of Plasmodium falciparum isolates: an efficient and scalable tool to quantify prevailing malaria drug-resistance genotypes.

    Science.gov (United States)

    Taylor, Steve M; Parobek, Christian M; Aragam, Nash; Ngasala, Billy E; Mårtensson, Andreas; Meshnick, Steven R; Juliano, Jonathan J

    2013-12-15

    Molecular surveillance for drug-resistant malaria parasites requires reliable, timely, and scalable methods. These data may be efficiently produced by genotyping parasite populations using second-generation sequencing (SGS). We designed and validated a SGS protocol to quantify mutant allele frequencies in the Plasmodium falciparum genes dhfr and dhps in mixed isolates. We applied this new protocol to field isolates from children and compared it to standard genotyping using Sanger sequencing. The SGS protocol accurately quantified dhfr and dhps allele frequencies in a mixture of parasite strains. Using SGS of DNA that was extracted and then pooled from individual isolates, we estimated mutant allele frequencies that were closely correlated to those estimated by Sanger sequencing (correlations, >0.98). The SGS protocol obviated most molecular steps in conventional methods and is cost saving for parasite populations >50. This SGS genotyping method efficiently and reproducibly estimates parasite allele frequencies within populations of P. falciparum for molecular epidemiologic studies.

  2. Genotyping-by-sequencing-based genome-wide association studies on Verticillium wilt resistance in autotetraploid alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Yu, Long-Xi; Zheng, Ping; Zhang, Tiejun; Rodringuez, Jonas; Main, Dorrie

    2017-02-01

    Verticillium wilt (VW) is a fungal disease that causes severe yield losses in alfalfa. The most effective method to control the disease is through the development and use of resistant varieties. The identification of marker loci linked to VW resistance can facilitate breeding for disease-resistant alfalfa. In the present investigation, we applied an integrated framework of genome-wide association with genotyping-by-sequencing (GBS) to identify VW resistance loci in a panel of elite alfalfa breeding lines. Phenotyping was performed by manual inoculation of the pathogen to healthy seedlings, and scoring for disease resistance was carried out according to the standard test of the North America Alfalfa Improvement Conference (NAAIC). Marker-trait association by linkage disequilibrium identified 10 single nucleotide polymorphism (SNP) markers significantly associated with VW resistance. Alignment of the SNP marker sequences to the M. truncatula genome revealed multiple quantitative trait loci (QTLs). Three, two, one and five markers were located on chromosomes 5, 6, 7 and 8, respectively. Resistance loci found on chromosomes 7 and 8 in the present study co-localized with the QTLs reported previously. A pairwise alignment (blastn) using the flanking sequences of the resistance loci against the M. truncatula genome identified potential candidate genes with putative disease resistance function. With further investigation, these markers may be implemented into breeding programmes using marker-assisted selection, ultimately leading to improved VW resistance in alfalfa. PUBLISHED 2016. THIS ARTICLE IS A U.S. GOVERNMENT WORK AND IS IN THE PUBLIC DOMAIN IN THE USA.

  3. Overexpression of ShCYP51B and ShatrD in Sclerotinia homoeocarpa isolates exhibiting practical field resistance to a demethylation inhibitor fungicide.

    Science.gov (United States)

    Hulvey, Jon; Popko, James T; Sang, Hyunkyu; Berg, Andrew; Jung, Geunhwa

    2012-09-01

    We investigated genetic factors that govern the reduced propiconazole sensitivity of Sclerotinia homoeocarpa field isolates collected during a 2-year field efficacy study on dollar spot disease of turf in five New England sites. These isolates displayed a >50-fold range of in vitro sensitivity to a sterol demethylation inhibitor (DMI) fungicide, propiconazole, making them ideal for investigations of genetic mechanisms of reduced DMI sensitivity. The CYP51 gene homolog in S. homoeocarpa (ShCYP51B), encoding the enzyme target of DMIs, is likely a minor genetic factor for reduced propiconazole sensitivity, since there were no differences in constitutive relative expression (RE) values and only 2-fold-higher induced RE values for insensitive than for sensitive isolate groups. Next, we mined RNA-Seq transcriptome data for additional genetic factors and found evidence for the overexpression of a homolog of Botrytis cinerea atrD (BcatrD), ShatrD, a known efflux transporter of DMI fungicides. The ShatrD gene showed much higher constitutive and induced RE values for insensitive isolates. Several polymorphisms were found upstream of ShatrD but were not definitively linked to overexpression. The screening of constitutive RE values of ShCYP51B and ShatrD in isolates from two golf courses that exhibited practical field resistance to propiconazole uncovered evidence for significant population-specific overexpression of both genes. However, linear regression demonstrated that the RE of ShatrD displays a more significant relationship with propiconazole sensitivity than that of ShCYP51B. In summary, our results suggest that efflux is a major determinant of the reduced DMI sensitivity of S. homoeocarpa genotypes in New England, which may have implications for the emergence of practical field resistance in this important turfgrass pathogen.

  4. Mice Deficient in Proglucagon-Derived Peptides Exhibit Glucose Intolerance on a High-Fat Diet but Are Resistant to Obesity.

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    Yusuke Takagi

    Full Text Available Homozygous glucagon-GFP knock-in mice (Gcggfp/gfp lack proglucagon derived-peptides including glucagon and GLP-1, and are normoglycemic. We have previously shown that Gcggfp/gfp show improved glucose tolerance with enhanced insulin secretion. Here, we studied glucose and energy metabolism in Gcggfp/gfp mice fed a high-fat diet (HFD. Male Gcggfp/gfp and Gcggfp/+ mice were fed either a normal chow diet (NCD or an HFD for 15-20 weeks. Regardless of the genotype, mice on an HFD showed glucose intolerance, and Gcggfp/gfp mice on HFD exhibited impaired insulin secretion whereas Gcggfp/+ mice on HFD exhibited increased insulin secretion. A compensatory increase in β-cell mass was observed in Gcggfp/+mice on HFD, but not in Gcggfp/gfp mice on the same diet. Weight gain was significantly lower in Gcggfp/gfp mice than in Gcggfp/+mice. Oxygen consumption was enhanced in Gcggfp/gfp mice compared to Gcggfp/+ mice on an HFD. HFD feeding significantly increased uncoupling protein 1 mRNA expression in brown adipose and inguinal white adipose tissues of Gcggfp/gfp mice, but not of Gcggfp/+mice. Treatment with the glucagon-like peptide-1 receptor agonist liraglutide (200 mg/kg improved glucose tolerance in Gcggfp/gfp mice and insulin content in Gcggfp/gfp and Gcggfp/+ mice was similar after liraglutide treatment. Our findings demonstrate that Gcggfp/gfp mice develop diabetes upon HFD-feeding in the absence of proglucagon-derived peptides, although they are resistant to diet-induced obesity.

  5. Fitness Cost of Fluoroquinolone Resistance in Clinical Isolates of Pseudomonas aeruginosa Differs by Type III Secretion Genotype

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    Melissa Agnello

    2016-10-01

    Full Text Available Fluoroquinolone (FQ resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment. We created isogenic mutants containing a common FQ-resistance conferring point mutation in parC from 3 exoU and 3 exoS clinical isolates and tested fitness in vitro using head-to-head competition assays. The mutation differentially affected fitness in the exoU and exoS strains tested. While the addition of the parC mutation dramatically increased fitness in one of the exoU strains leaving the other two unaffected, all three exoS strains displayed a general decrease in fitness. In addition, we found that exoU strains may be able to compensate for the fitness costs associated with the mutation through better regulation of supercoiling compared to the exoS strains. These results may provide a biological explanation for the observed predominance of the virulent exoU genotype in FQ-resistant clinical subpopulations and represent the first investigation into potential differences in fitness costs of FQ-resistance that are linked to the virulence genotype of P. aeruginosa. Understanding the fitness costs of antibiotic resistance and possibilities of compensation for these costs is essential for the rational development of strategies to combat the problem of antibiotic resistance.

  6. Fitness Cost of Fluoroquinolone Resistance in Clinical Isolates of Pseudomonas aeruginosa Differs by Type III Secretion Genotype

    Science.gov (United States)

    Agnello, Melissa; Finkel, Steven E.; Wong-Beringer, Annie

    2016-01-01

    Fluoroquinolone (FQ) resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment. We created isogenic mutants containing a common FQ-resistance conferring point mutation in parC from three exoU to three exoS clinical isolates and tested fitness in vitro using head-to-head competition assays. The mutation differentially affected fitness in the exoU and exoS strains tested. While the addition of the parC mutation dramatically increased fitness in one of the exoU strains leaving the other two unaffected, all three exoS strains displayed a general decrease in fitness. In addition, we found that exoU strains may be able to compensate for the fitness costs associated with the mutation through better regulation of supercoiling compared to the exoS strains. These results may provide a biological explanation for the observed predominance of the virulent exoU genotype in FQ-resistant clinical subpopulations and represent the first investigation into potential differences in fitness costs of FQ-resistance that are linked to the virulence genotype of P. aeruginosa. Understanding the fitness costs of antibiotic resistance and possibilities of compensation for these costs is essential for the rational development of strategies to combat the problem of antibiotic resistance.

  7. Resistance evaluation of Chinese wild Vitis genotypes against Botrytis cinerea and different responses of resistant and susceptible hosts to the infection

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    Ran eWan

    2015-10-01

    Full Text Available The necrotrophic fungus Botrytis cinerea is a major threat to grapevine cultivation worldwide. A screen of 41 Vitis genotypes for leaf resistance to B. cinerea suggested species independent variation and revealed eighteen resistant Chinese wild Vitis genotypes, while most investigated V. vinifera, or its hybrids, were susceptible. A particularly resistant Chinese wild Vitis, ‘Pingli-5’ (V. sp. [Qinling grape] and a very susceptible V. vinifera cultivar, ‘Red Globe’ were selected for further study. Microscopic analysis demonstrated that B. cinerea growth was limitted during early infection on ‘Pingli-5’ before 24 hours post inoculation (hpi but not on Red Globe. It was found that reactive oxygen species (ROS and antioxidative system were associated with fungal growth. O2- accumulated similarly in B. cinerea 4 hpi on both Vitis genotypes. Lower levels of O2- (not H2O2 were detected 4 hpi and ROS (H2O2 and O2- accumulation from 8 hpi onwards was also lower in ‘Pingli-5’ leaves than in ‘Red Globe’ leaves. B. cinerea triggered sustained ROS production in ‘Red Globe’ but not in ‘Pingli-5’ with subsequent infection progresses. Red Globe displayed little change in antioxidative activities in response to B. cinerea infection, instead, antioxidative activities were highly and timely elevated in resistant ‘Pingli-5’ which correlated with its minimal ROS increases and its high resistance. These findings not only enhance our understanding of the resistance of Chinese wild Vitis species to B. cinerea, but also lay the foundation for breeding B. cinerea resistant grapes in the future.

  8. Transgenic rice plants expressing the snowdrop lectin gene (gna) exhibit high-level resistance to the whitebacked planthopper (Sogatella furcifera).

    Science.gov (United States)

    Nagadhara, D; Ramesh, S; Pasalu, I C; Rao, Y Kondala; Sarma, N P; Reddy, V D; Rao, K V

    2004-11-01

    Transgenic rice plants, expressing snowdrop lectin [Galanthus nivalis agglutinin (GNA)], obtained by Agrobacterium-mediated genetic transformation, were evaluated for resistance against the insect, the whitebacked planthopper (WBPH). The transgene gna was driven by the phloem-specific, rice-sucrose synthase promoter RSs1, and the bar was driven by the CaMV 35S promoter. In our previous study, the transgenic status of these lines was confirmed by Southern, Northern and Western blot analyses. Both the transgenes, gna and bar, were stably inherited and co-segregated into progenies in T1 to T5 generations. Insect bioassays on transgenic plants revealed the potent entomotoxic effects of GNA on the WBPH. Also, significant decreases were observed in the survival, development and fecundity of the insects fed on transgenic plants. Furthermore, intact GNA was detected in the total proteins of WBPHs fed on these plants. Western blot analysis revealed stable and consistent expression of GNA throughout the growth and development of transgenic plants. Transgenic lines expressing GNA exhibited high-level resistance against the WBPH. As reported earlier, these transgenics also showed substantial resistance against the brown planthopper and green leafhopper.

  9. Genotypes, Antibiotic Resistance, and ST-8 Genetic Clone in Campylobacter Isolates from Sheep and Goats in Grenada

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    Diana M. Stone

    2014-01-01

    Full Text Available Rectal swabs from 155 sheep and 252 goats from Grenada were evaluated to determine the prevalence of Campylobacter spp., antibiotic resistance, and multilocus sequence types. Fifteen Campylobacter isolates were obtained (14 C. jejuni and 1 C. coli. The prevalence (3.7% did not differ significantly between sheep (4.5% and goats (3.2%. Among the seven antimicrobials tested, resistance was only detected for tetracycline (30.8% and metronidazole (38.5%. Campylobacter isolates showed no significant difference between sheep and goats for type of antimicrobial resistance or percent of resistant isolates. Twelve of the isolates were successfully genotyped consisting of four recognized clonal complexes and three novel sequence types. Importantly, one isolate from one goat was identified as the C. jejuni sequence type-8, a zoonotic and tetracycline-resistant clone reported to be a highly virulent clone associated with ovine abortion in the USA. Although most samples were from comingled sheep and goat production units, there were no shared sequence types between these two host species. None of the sequence types identified in this study have previously been reported in poultry in Grenada, suggesting sheep- and goat-specific Campylobacter clones in Grenada. This is the first report of genotyping of Campylobacter isolates from sheep and goats in the Eastern Caribbean.

  10. Genotypes, Antibiotic Resistance, and ST-8 Genetic Clone in Campylobacter Isolates from Sheep and Goats in Grenada.

    Science.gov (United States)

    Stone, Diana M; Chander, Yogesh; Bekele, Aschalew Z; Goyal, Sagar M; Hariharan, Harry; Tiwari, Keshaw; Chikweto, Alfred; Sharma, Ravindra

    2014-01-01

    Rectal swabs from 155 sheep and 252 goats from Grenada were evaluated to determine the prevalence of Campylobacter spp., antibiotic resistance, and multilocus sequence types. Fifteen Campylobacter isolates were obtained (14 C. jejuni and 1 C. coli). The prevalence (3.7%) did not differ significantly between sheep (4.5%) and goats (3.2%). Among the seven antimicrobials tested, resistance was only detected for tetracycline (30.8%) and metronidazole (38.5%). Campylobacter isolates showed no significant difference between sheep and goats for type of antimicrobial resistance or percent of resistant isolates. Twelve of the isolates were successfully genotyped consisting of four recognized clonal complexes and three novel sequence types. Importantly, one isolate from one goat was identified as the C. jejuni sequence type-8, a zoonotic and tetracycline-resistant clone reported to be a highly virulent clone associated with ovine abortion in the USA. Although most samples were from comingled sheep and goat production units, there were no shared sequence types between these two host species. None of the sequence types identified in this study have previously been reported in poultry in Grenada, suggesting sheep- and goat-specific Campylobacter clones in Grenada. This is the first report of genotyping of Campylobacter isolates from sheep and goats in the Eastern Caribbean.

  11. STAPHYLOCOCCUS AUREUS ISOLATES FROM CAMELS DIFFER IN COAGULASE PRODUCTION, GENOTYPE AND METHICILLIN RESISTANCE GENE PROFILES

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    Ziad Jaradat

    2013-06-01

    Full Text Available Accurate and rapid typing of S. aureus is crucial to the control of its infections and minimizing its leakage to the food chain. The primary purpose of this research was to isolate S. aureus from camels’ meat and nasal swabs and to characterize the isolates for coagulase production and the presence of methicillin gene using PCR-RFLP of coagulase gene. A total of 264 camel’s meat and nasal swabs were collected from abattoirs or meat markets and were used in the study. Ninety two percent of samples showed typical colonies of S. aureus on Baird-Parker agar with a mean count 2.5 × 104 ± 1.8 × 104 CFU g-1. Upon confirmation of the isolates using S. aureus specific thermonuclease gene (nuc PCR primers, only 64 isolates contained the specific product and thus were confirmed as S. aureus. However, when tested for the presence of coagulase gene, only 48 of them were positive while the other 16 were coagulase negative. Coagulase gene-RFLP revealed 19 distinct patterns when the gene was digested with Alu I and Cfo I. The typing revealed that the 48 classified isolates were genetically diverse and comprised a heterogeneous population with 14 genotypes at a 44.4% similarity level. When the coagulase positive isolates were tested for the presence of methicillin resistance (mec A gene, 37 of the isolates were positive while the other 11 isolates were negative. The high heterogeneity among S. aureus isolates might be due to cross contamination between camel carcasses in slaughter houses and from handlers and their utensils.

  12. Effects of Nitrogen Application Rate and Ratio on Lodging Resistance of Super Rice with Different Genotypes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wu-jun; LI Gang-hua; YANG Yi-ming; LI Quan; ZHANG Jun; LIU Jin-you; WANG Shao-hua; TANG She; DING Yan-feng

    2014-01-01

    The objective of this study was to determine the morphology mechanism of nitrogen (N) fertilizer rates and ratio on lodging resistance through analying its effects among lodging index (LI), lodging-related morphological traits and physical strength in basal internodes by comparing japonica and indica super rice cultivars. Field experiments, with three nitrogen levels (0, 150 and 300 kg ha-1) and two ratios of basal to topdressing (8:2 and 5:5) with two super rice cultivars (Yliangyou 2 and Wuyunjing 23), were conducted in the Baolin Farm, Danyang Country, Jiangsu Province, China, in 2011 and 2012. Effects of N fertilizer rates and ratios on morphology of whole plant, morphology traits in basal internodes and culm’s physical strength parameters were investigated at 20 d after full heading stage. LI of Yliangyou 2 was signiifcant greater than that of Wuyunjing 23 due to larger bending moment by whole plant (WP) with higher plant height and gravity center height. With higher volume of N fertilizer, LI of two super rice cultivars was increased conspicuously. However, no signiifcant effect was detected with increase of panicle fertilizer ratio. The size of breaking strength (M) in basal internodes was the key factor determining LI among N fertilizer treatments. Correlation analysis revealed that M value was positively related bending stress (BS) of Wuyunjing 23 and section modulus (Z) of Yliangyou 2, respectively. The higher N fertilizer levels induced reduction of BS of Wuyunjing 23 due to weak culm and leaf sheath plumpness status and reduced Z of Yliangyou 2 owning to small diameter and culm wall thickness, consequently, inlfuencing their M indirectly. These results suggested that breaking strength was the key factor inlfuencing LI with increase of N fertilizer levels. However, the lodging-related morphology mechanism was different with genotypes. Culm wall thickness and diameter in basal internodes of indica super rice and culm and leaf sheath plumpness status of

  13. Persistence of Escherichia coli clones and phenotypic and genotypic antibiotic resistance in recurrent urinary tract infections in childhood

    DEFF Research Database (Denmark)

    Kõljalg, Siiri; Truusalu, Kai; Vainumäe, Inga

    2009-01-01

    We assessed the clonality of consecutive Escherichia coli isolates during the course of recurrent urinary tract infections (RUTI) in childhood in order to compare clonality with phenotypic antibiotic resistance patterns, the presence of integrons, and the presence of the sul1, sul2, and sul3 genes...... and the presence or absence of the intI gene for class 1 integrons and the sulfamethoxazole resistance-encoding genes sul1, sul2, and sul3 were determined. All E. coli strains were genotyped by pulsed-field gel electrophoresis. There were no significant differences in the prevalences of resistance to beta......% of the patients, the recurrence of unique clonal E. coli strains alone or combined with individual strains was detected. Phenotypic resistance and the occurrence of sul genes were more stable in clonal strains than in individual strains (odds ratios, 8.7 [95% confidence interval {95% CI}, 1.8 to 40.8] and 4.4 [95...

  14. Pheno- and genotypic analysis of antimicrobial resistance properties of Yersinia ruckeri from fish.

    Science.gov (United States)

    Huang, Yidan; Michael, Geovana Brenner; Becker, Roswitha; Kaspar, Heike; Mankertz, Joachim; Schwarz, Stefan; Runge, Martin; Steinhagen, Dieter

    2014-07-16

    Enteric red-mouth disease, caused by Yersinia ruckeri, is an important disease in rainbow trout aquaculture. Antimicrobial agents are frequently used in aquaculture, thereby causing a selective pressure on bacteria from aquatic organisms under which they may develop resistance to antimicrobial agents. In this study, the distribution of minimal inhibitory concentrations (MICs) of antimicrobial agents for 83 clinical and non-clinical epidemiologically unrelated Y. ruckeri isolates from north west Germany was determined. Antimicrobial susceptibility was conducted by broth microdilution at 22 ± 2°C for 24, 28 and 48 h. Incubation for 24h at 22 ± 2°C appeared to be suitable for susceptibility testing of Y. ruckeri. In contrast to other antimicrobial agents tested, enrofloxacin and nalidixic acid showed a bimodal distribution of MICs, with one subpopulation showing lower MICs for enrofloxacin (0.008-0.015 μg/mL) and nalidixic acid (0.25-0.5 μg/mL) and another subpopulation exhibiting elevated MICs of 0.06-0.25 and 8-64 μg/mL, respectively. Isolates showing elevated MICs revealed single amino acid substitutions in the quinolone resistance-determining region (QRDR) of the GyrA protein at positions 83 (Ser83-Arg or -Ile) or 87 (Asn87-Tyr), which raised the MIC values 8- to 32-fold for enrofloxacin or 32- to 128-fold for nalidixic acid. An isolate showing elevated MICs for sulfonamides and trimethoprim harbored a ∼ 8.9 kb plasmid, which carried the genes sul2, strB and a dfrA14 gene cassette integrated into the strA gene. These observations showed that Y. ruckeri isolates were able to develop mutations that reduce their susceptibility to (fluoro)quinolones and to acquire plasmid-borne resistance genes. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    Science.gov (United States)

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

  16. Root transcriptional responses of two melon genotypes with contrasting resistance to Monosporascus cannonballus (Pollack et Uecker infection

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    Roig Cristina

    2012-11-01

    Full Text Available Abstract Background Monosporascus cannonballus is the main causal agent of melon vine decline disease. Several studies have been carried out mainly focused on the study of the penetration of this pathogen into melon roots, the evaluation of symptoms severity on infected roots, and screening assays for breeding programs. However, a detailed molecular view on the early interaction between M. cannonballus and melon roots in either susceptible or resistant genotypes is lacking. In the present study, we used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes, Cucumis melo ‘Piel de sapo’ (‘PS’ and C. melo ‘Pat 81’, with contrasting resistance to the disease. This study was carried out at 1 and 3 days after infection (DPI by M. cannonballus. Results Our results indicate a dissimilar behavior of the susceptible vs. the resistant genotypes from 1 to 3 DPI. ‘PS’ responded with a more rapid infection response than ‘Pat 81’ at 1 DPI. At 3 DPI the total number of differentially expressed genes identified in ‘PS’ declined from 451 to 359, while the total number of differentially expressed transcripts in ‘Pat 81’ increased from 187 to 849. Several deregulated transcripts coded for components of Ca2+ and jasmonic acid (JA signalling pathways, as well as for other proteins related to defence mechanisms. Transcriptional differences in the activation of the JA-mediated response in ‘Pat 81’ compared to ‘PS’ suggested that JA response might be partially responsible for their observed differences in resistance. Conclusions As a result of this study we have identified for the first time a set of candidate genes involved in the root response to the infection of the pathogen causing melon vine decline. This information is useful for understanding the disease progression and resistance mechanisms few days after inoculation.

  17. Transgenic rice expressing Allium sativum leaf agglutinin (ASAL exhibits high-level resistance against major sap-sucking pests

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    Vudem Dasavantha

    2008-10-01

    plants, bestowed with high entomotoxic effects, imparted appreciable resistance against three major sap-sucking insects. Our results amply demonstrate that transgenic indica rice harbouring asal exhibit surpassing resistance against BPH, GLH and WBPH insects. The prototypic asal transgenic rice lines appear promising for direct commercial cultivation besides serving as a potential genetic resource in recombination breeding.

  18. Innate immune markers that distinguish red deer (Cervus elaphus selected for resistant or susceptible genotypes for Johne’s disease

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    Dobson Brooke

    2013-01-01

    Full Text Available Abstract While many factors contribute to resistance and susceptibility to infectious disease, a major component is the genotype of the host and the way in which it is expressed. Johne’s disease is a chronic inflammatory bowel disease affecting ruminants and is caused by infection with Mycobacterium avium subspecies paratuberculosis (MAP. We have previously identified red deer breeds (Cervus elaphus that are resistant; have a low rate of MAP infection and do not progress to develop Johne’s disease. In contrast, susceptible breeds have a high rate of MAP infection as seen by seroconversion and progress to develop clinical Johne’s disease. The aim of this study was to determine if immunological differences exist between animals of resistant or susceptible breeds. Macrophage cultures were derived from the monocytes of deer genotypically defined as resistant or susceptible to the development of Johne’s disease. Following in vitro infection of the cells with MAP, the expression of candidate genes was assessed by quantitative PCR as well as infection rate and cell death rate. The results indicate that macrophages from susceptible animals show a significantly higher upregulation of inflammatory genes (iNOS, IL-1α, TNF-α and IL-23p19 than the macrophages from resistant animals. Cells from resistant animals had a higher rate of apoptosis at 24 hours post infection (hpi compared to macrophages from susceptible animals. The excessive expression of inflammatory mRNA transcripts in susceptible animals could cause inefficient clearing of the mycobacterial organism and the establishment of disease. Controlled upregulation of inflammatory pathways coupled with programmed cell death in the macrophages of resistant animals may predispose the host to a protective immune response against this mycobacterial pathogen.

  19. Genotypic relatedness and antimicrobial resistance of Salmonella Heidelberg isolated from chickens and turkeys in the midwestern United States.

    Science.gov (United States)

    Nisar, Muhammad; Kassem, Issmat I; Rajashekara, Gireesh; Goyal, Sagar M; Lauer, Dale; Voss, Shauna; Nagaraja, Kakambi V

    2017-05-01

    Salmonella is one of the most common causes of foodborne illnesses in humans in the United States, and domestic poultry is considered an important source of this pathogen. Salmonella enterica subsp. enterica serovar Heidelberg is the fourth most commonly reported Salmonella from retail meats and food animals in the United States. We assessed the genotypes and antimicrobial resistance phenotypes of Salmonella Heidelberg isolated from various chicken and turkey hatcheries and breeder farms in the Midwest. The genotypes of 33 S. Heidelberg isolates from chickens ( n = 19) and turkeys ( n = 14) were compared using pulsed-field gel electrophoresis analysis. Cluster analysis of the fingerprints showed that the majority of the chicken isolates grouped together with 87% similarity; those from turkeys clustered with 88% similarity. Similarity between chicken and turkey isolates was also high (86%). Isolates from turkeys were generally more genetically diverse than those from chickens. Antimicrobial susceptibility analysis detected resistance to sulfisoxazole (36% of the isolates), streptomycin (33%), gentamicin (27%), tetracycline (24%), ampicillin and amoxicillin-clavulanic acid (15%), cefoxitin (12%), ceftriaxone and ceftiofur (12%), and chloramphenicol (9%). None of the isolates was resistant to azithromycin, ciprofloxacin, or nalidixic acid. Although the number of the isolates was limited in our study, we conclude that S. Heidelberg isolates from the same host generally clustered together and that a considerable number of the isolates were resistant to a number of antimicrobial agents.

  20. Transcript dynamics at early stages of molecular interactions of MYMIV with resistant and susceptible genotypes of the leguminous host, Vigna mungo.

    Science.gov (United States)

    Kundu, Anirban; Patel, Anju; Paul, Sujay; Pal, Amita

    2015-01-01

    Initial phases of the MYMIV-Vigna mungo interaction is crucial in determining the infection phenotype upon challenging with the virus. During incompatible interaction, the plant deploys multiple stratagems that include extensive transcriptional alterations defying the virulence factors of the pathogen. Such molecular events are not frequently addressed by genomic tools. In order to obtain a critical insight to unravel how V. mungo respond to Mungbean yellow mosaic India virus (MYMIV), we have employed the PCR based suppression subtractive hybridization technique to identify genes that exhibit altered expressions. Dynamics of 345 candidate genes are illustrated that differentially expressed either in compatible or incompatible reactions and their possible biological and cellular functions are predicted. The MYMIV-induced physiological aspects of the resistant host include reactive oxygen species generation, induction of Ca2+ mediated signaling, enhanced expression of transcripts involved in phenylpropanoid and ubiquitin-proteasomal pathways; all these together confer resistance against the invader. Elicitation of genes implicated in salicylic acid (SA) pathway suggests that immune response is under the regulation of SA signaling. A significant fraction of modulated transcripts are of unknown function indicating participation of novel candidate genes in restricting this viral pathogen. Susceptibility on the other hand, as exhibited by V. mungo Cv. T9 is perhaps due to the poor execution of these transcript modulation exhibiting remarkable repression of photosynthesis related genes resulting in chlorosis of leaves followed by penalty in crop yield. Thus, the present findings revealed an insight on the molecular warfare during host-virus interaction suggesting plausible signaling mechanisms and key biochemical pathways overriding MYMIV invasion in resistant genotype of V. mungo. In addition to inflate the existing knowledge base, the genomic resources identified in

  1. Transcript dynamics at early stages of molecular interactions of MYMIV with resistant and susceptible genotypes of the leguminous host, Vigna mungo.

    Directory of Open Access Journals (Sweden)

    Anirban Kundu

    Full Text Available Initial phases of the MYMIV-Vigna mungo interaction is crucial in determining the infection phenotype upon challenging with the virus. During incompatible interaction, the plant deploys multiple stratagems that include extensive transcriptional alterations defying the virulence factors of the pathogen. Such molecular events are not frequently addressed by genomic tools. In order to obtain a critical insight to unravel how V. mungo respond to Mungbean yellow mosaic India virus (MYMIV, we have employed the PCR based suppression subtractive hybridization technique to identify genes that exhibit altered expressions. Dynamics of 345 candidate genes are illustrated that differentially expressed either in compatible or incompatible reactions and their possible biological and cellular functions are predicted. The MYMIV-induced physiological aspects of the resistant host include reactive oxygen species generation, induction of Ca2+ mediated signaling, enhanced expression of transcripts involved in phenylpropanoid and ubiquitin-proteasomal pathways; all these together confer resistance against the invader. Elicitation of genes implicated in salicylic acid (SA pathway suggests that immune response is under the regulation of SA signaling. A significant fraction of modulated transcripts are of unknown function indicating participation of novel candidate genes in restricting this viral pathogen. Susceptibility on the other hand, as exhibited by V. mungo Cv. T9 is perhaps due to the poor execution of these transcript modulation exhibiting remarkable repression of photosynthesis related genes resulting in chlorosis of leaves followed by penalty in crop yield. Thus, the present findings revealed an insight on the molecular warfare during host-virus interaction suggesting plausible signaling mechanisms and key biochemical pathways overriding MYMIV invasion in resistant genotype of V. mungo. In addition to inflate the existing knowledge base, the genomic resources

  2. Genotypic drug resistance and long-term mortality in patients with triple-class antiretroviral drug failure

    DEFF Research Database (Denmark)

    Lohse, Nicolai; Jørgensen, Louise B; Kronborg, Gitte

    2007-01-01

    in the DHCS who experienced TCF between January 1995 and November 2004, and we performed genotypic resistance tests for International AIDS Society (IAS)-USA primary mutations on virus from plasma samples taken around the date of TCF. We computed time to all-cause death from date of TCF. The relative risk...... with increased mortality (mortality rate ratio [MRR] 2.3 [95% confidence interval (CI) 1.1-4.8]), as were the individual mutations T215Y (MRR 3.4 [95% CI 1.6-7.0]), G190A/S (MRR 3.2 [95% CI 1.6-6.6]) and V82F/A/T/S (MRR 2.5 [95% CI 1.2-5.3]). CONCLUSIONS: In HIV patients with TCF, the total number of genotypic...... HIV Cohort Study (DHCS). METHODS: We included all patients in the DHCS who experienced TCF between January 1995 and November 2004, and we performed genotypic resistance tests for International AIDS Society (IAS)-USA primary mutations on virus from plasma samples taken around the date of TCF. We...

  3. EVALUATION OF DISEASE RESISTANCE POTENTIAL OF SEVEN POTATO GENOTYPES AGAINST EARLY BLIGHT CAUSED BY Alternaria tenuissima UNDER GREENHOUSE CONDITIONS

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mirkarimi

    2013-07-01

    Full Text Available Early blight of potato was caused by various species of genus Alternaria, the disease has a prominent role in reducing crop yields in most of the countries, especially in Iran. Various studies has been conducted for the finding out the information regarding the diversity of pathogen and estimation of damage caused by genus Alternaria tenuissima in Iran, but the information regarding the resistance against this fungal pathogen in various genotype of potatoes are in scarcity. Seven isolates of potato were obtained from the National Plant Gene Bank of Iran. Amongst these seven, on the basis of mean comparison curve progress Cosmos was recognized as the most sensitive genetic samples while the samples Armida was reported as a most resistant to the disease. Other cultivars showed different levels of resistance against this pathogen.

  4. Genotypic drug resistance and long-term mortality in patients with triple-class antiretroviral drug failure

    DEFF Research Database (Denmark)

    Lohse, Nicolai; Jørgensen, Louise B; Kronborg, Gitte

    2007-01-01

    in the DHCS who experienced TCF between January 1995 and November 2004, and we performed genotypic resistance tests for International AIDS Society (IAS)-USA primary mutations on virus from plasma samples taken around the date of TCF. We computed time to all-cause death from date of TCF. The relative risk...... with increased mortality (mortality rate ratio [MRR] 2.3 [95% confidence interval (CI) 1.1-4.8]), as were the individual mutations T215Y (MRR 3.4 [95% CI 1.6-7.0]), G190A/S (MRR 3.2 [95% CI 1.6-6.6]) and V82F/A/T/S (MRR 2.5 [95% CI 1.2-5.3]). CONCLUSIONS: In HIV patients with TCF, the total number of genotypic...

  5. Compatibility of Intercropping Stem Borer Resistant Sorghum Sorghum bicolor Moench Genotypes with Cowpea Vigna unguiculata (L Walp and its Effect on Flower Thrips

    Directory of Open Access Journals (Sweden)

    Ampong-Nyarko, K.

    1994-01-01

    Full Text Available The compatibility of sorghum Sorghum bicolor Moench genotypes with varying levels of resistance to stem borers for intercropping was studied in field experiments for two cropping seasons at the ICIPE in Kenya. Sorghum genotypes IS-18520, IS-1044, IS-2269, ICS 3, ICS 4, LRB6, 2Kx17and Gaddam El Hamam were grown both as monocrops and as intercrops with cowpea. Intercropping reduced the Chilo partellus population density but there was no significant genotype x intercropping interaction. Intercropping significantly reduced the number of flower thrips Megalurothrips sjostedti in cowpea Vigna unguiculata (L Walp. The stem borer resistance level of sorghum genotypes tested was not affected by intercropping. There were, however, differences in agronomic productivity. Grain yield of intercropped sorghum was positively correlated with the number of tillers per harvestable head. Sorghum genotypes with high tillering capacity, of intermediate plant height and intermediate leaf area were considered compatible for intercropping with cowpea.

  6. Prion protein genotype survey confirms low frequency of scrapie-resistant K222 allele in British goat herds.

    Science.gov (United States)

    Goldmann, W; Marier, E; Stewart, P; Konold, T; Street, S; Langeveld, J; Windl, O; Ortiz-Pelaez, A

    2016-02-13

    Scrapie in goats is a transmissible, fatal prion disease, which is endemic in the British goat population. The recent success in defining caprine PRNP gene variants that provide resistance to experimental and natural classical scrapie has prompted the authors to conduct a survey of PRNP genotypes in 10 goat breeds and 52 herds to find goats with the resistant K222 allele. They report here the frequencies in 1236 tested animals of the resistance-associated K222 and several other alleles by breed and herd. Eight animals were found to be heterozygous QK222 goats (0.64 per cent genotype frequency, 95 per cent CI 0.28 to 1.27 per cent) but no homozygous KK222 goats were detected. The K222 allele was found in Saanen, Toggenburg and Anglo-Nubian goats. The fact that only a few goats with the K222 allele have been identified does not preclude the possibility to design and implement successful breeding programmes at national level.

  7. Prevalence of Enterotoxin Genes and spa Genotypes of Methicillin-resistant Staphylococcus aureus from a Tertiary Care Hospital in China.

    Science.gov (United States)

    Li, Yanmeng; Zhao, Ruike; Zhang, Xianfeng; Han, Qingzhen; Qian, Xuefeng; Gu, Guohao; Shi, Jinfang; Xu, Jie

    2015-05-01

    Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes a variety of infections. MRSA has evolved resistance to multiple antibiotics. Genetic background and virulence differs in different geographic regions. The present study was aimed to investigate the prevalence of enterotoxin genes and spa genotypes of hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) isolated from a tertiary care hospital of Jiangsu province, China. HA-MRSA isolates from August 2013 to April 2014 at a tertiary care hospital of China were collected. We investigated antimicrobial pattern, spa types, SCCmec types and the presence of 14 virulence genes. Eighty HA-MRSA isolates were collected. Results from SCCmec typing revealed that 73.8% were type II; 13.8% were type III; 12.5% were type V. There were 19 different spa types. Spa type t2460 was the most common (35.0%), followed by t002 (11.3%). CC5 was the predominant MLST CCs type (50%). The most frequent toxin genes were sea, seb, sed, sel, sen and seo (100.0%). None of the investigated isolates carried the sec or tst. Genotypic and virulence evaluation of the isolated HA-MRSA revealed that the isolates with CC5 and SCCmec II were the predominant type and highly homological. The virulence profiles mainly existed in the genes of sea, seb, sed, sel, sen, seo and ser. The prevalence of t2460 was an outbreak and the predominant spa type.

  8. Identification of HIV-1 Genotypic Resistance in Patients on First-line Antiretroviral Therapy Using Polymerase Chain Reaction and Sequencing

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Objective The aim of the study was to evaluate the characteristics of HIV drug-genotypic resistance among patients taking ifrst-line ARV regimens using polymerase chain reaction and sequencing, and guide to design optimal ARV regimens for these patients. Methods HIV reverse transcriptase-encoded gene was ampliifed with RT-PCR and ampliifed PCR products were aligned and comparatively analyzed with HIV resistance database to ifnd drug-resistance mutations. Results Twenty-eight PCR products were amplified and sequenced successfully in 30 serum samples of recruited HIV-infected patients with virologic failure. The resistance rate was 96%, mutations in NRT region were found in 26 patients (93%), while mutations in NNRT region were found in 27 patients (96%). M184V was the most common mutation (86%), K65R was selected in 14%of recruited individuals and TAMs occurred in 50%of patients, which resulted in resistance to NRTIs. Y181C and V179D were the most common mutations in NNRTIs and prevalence was 43%(12/28) and 36%(10/28), respectively, which resulted in cross-resistance to NNRTIs due to low-genetic barrier. Conclusions Virologic failure may occur in long-term administration of ifrst-line ARV regimens, and drug-resistance mutations can be found in these patients, which resulted in resistance to ifrst-line ARV regimens. We emphasized that HIV viral load assay and resistance assay were important tools to guide healthcare workers to design an optimal second-line ARV regimens for HAART-experienced individuals with virologic failure.

  9. Functional categorization of carbapenemase-mediated resistance by a combined genotyping and two-tiered Modified Hodge Test approach.

    Science.gov (United States)

    Wong, Marcus H; Li, Yi; Chan, Edward W; Chen, Sheng

    2015-01-01

    The functional relationship between the detection of carbapenemase activity and phenotypic resistance in Gram-negative bacterial pathogens is often ill-defined. To address this issue, we developed a two-tiered Modified Hodge Test approach for carbapenemase detection and typing, in which the use of Pseudomonas aeruginosa strain PAO1 and Escherichia coli as indicator strains conferred two levels of sensitivities to carbapenemases. When applied alongside PCR genotyping tests for existence of known carbapenemase genes in 92 carbapenem resistant clinical isolates, this method is extremely useful in elucidating the relative role by which different enzymes contributed to the prevalent carbapenem-resistance phenotypes. With this study approach, we showed that the proportion of P. aeruginosa and Acinetobacter baumannii strains whose carbapenem resistance phenotypes could at least be partially attributed to carbapenemase were 34 and 89%, respectively. Our data also facilitates detailed functional categorization of carbapenem resistance phenotypes on the basis of the types and activities of detectable carbapenemase produced by the test organism. For example, six A. baumannii isolates harboring the bla OXA-51/23-like gene without detectable enzymatic activities were identified, suggesting that other resistance mechanisms may be involved. On the other hand, there were seven P. aeruginosa strains which produced carbapenemase phenotype without harboring known carbapenemase genes, inferring the existence of some hitherto unknown resistance determinants. Findings in this work therefore provide a comprehensive view on the cellular basis of carbapenem resistance phenotypes in major Gram-negative bacterial species, paving the way for development of novel strategies to reverse the effects of the major resistance mechanisms concerned.

  10. Diagnosis of Drug Resistance to Fluoroquinolones, Amikacin, Capreomycin, Kanamycin and Ethambutol with Genotype MTBDRsl Assay: a Meta-Analysis.

    Science.gov (United States)

    Mao, Xiaolu; Ke, Zunqiong; Shi, Xiaoyan; Liu, Shuiyi; Tang, Beibei; Wang, Jin; Huang, Hao

    2015-01-01

    The Genotype MTBDRsl is a new-generation PCR-based line-probe assay for rapid identification of the resistance to the second-line antituberculosis drugs with a single strip. The aim of this meta-analysis was to evaluate the performance of Genotype MTBDRsl in detecting drug resistance to fluoroquinolones, amikacin, capreomycin, kanamycin and ethambutol in comparison with the phenotypic drug susceptibility test. We searched Pubmed, Embase and the Cochrane Library and calculated the sensitivity, the specificity, the positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), corresponding 95% confidence interval (CI), and the area under the summary receiver operating characteristic (SROC) curves (AUC), and tested heterogeneity in accuracy estimates with the Spearman correlation coefficient and Chi-square. The summarized sensitivity (95% CI), specificity (95% CI), and AUC (standard error) were 0.869 (0.847-0.890), 0.973 (0.965-0.979) and 0.9690 (0.0188) for fluoroquinolones, 0.868 (0.829-0.900), 0.998 (0.994-0.999) and 0.9944 (0.0050) for amikacin, 0.879 (0.838-0.914), 0.970 (0.958-0.978) and 0.9791 (0.0120) for capreomycin, 0.501 (0.461-0.541), 0.991 (0.983-0.996) and 0.9814 (0.0114) for kanamycin and 0.686 (0.663-0.709), 0.871 (0.852-0.888) and 0.7349 (0.0639) for ethambutol, respectively. The genotype MTBDRsl demonstrate excellent accuracy for detecting drug resistance to fluoroquinolones, amikacin, and capreomycin, but it may not be an appropriate choice for detection of kanamycin and ethambutol. © 2015 by the Association of Clinical Scientists, Inc.

  11. Avaliação da resistência a tobamovirus em acessos de Capsicum spp. Evaluation of resistance of Capsicum spp. genotypes to tobamovirus

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    Márcia Aparecida Cezar

    2009-02-01

    Full Text Available A resistência em Capsicum spp a tobamovírus é governada pelos genes L¹ a L4. Baseado na capacidade de alguns isolados suplantarem a resistência destes genes, os tobamovírus podem ser classificados nos patótipos P0, P1, P1-2 e P1-2-3. No Brasil, até o momento as três espécies de tobamovírus conhecidas são: Tobacco mosaic virus (TMV, Tomato mosaic virus (ToMV, pertencentes aos patótipos P0 e Pepper mild mottle virus (PMMoV pertencente ao patótipo P1-2, respectivamente e podem infectar pimentas e pimentões. Oitenta e seis genótipos de pimentão e pimenta foram avaliados quanto à resistência a tobamovírus, sendo 62 de Capsicum annuum, 18 de C. baccatum e seis de C. chinense. Oito acessos de C. annuum, seis de C. baccatum e os acessos ICA #39, Pimenta de cheiro e PI 152225 de C. chinense apresentaram reação de hipersensibilidade ao ToMV, enquanto que o acesso Ancho de C. annuum foi considerado tolerante, permanecendo assintomático, porém permitindo a recuperação do vírus quando inoculado em Nicotiana glutinosa. Para o PMMoV patótipo P1,2 foram avaliados os acessos de pimentão e pimenta considerados resistentes ao ToMV. Somente o PI 152225 de C. chinense desencadeou reação de hipersensibilidade ao PMMoV, sendo fonte potencial de resistência para programas de melhoramento a este vírus no Brasil.The resistance of Capsicum spp to tobamoviruses is conferred by the genes series L¹ to L4. Based on the ability of some isolates to overcome the resistance genes, the tobamovirus can be classificated in the pathotypes P0, P1, P1-2 and P1-2-3. In Brazil, at this moment there are three species of tobamovirus: Tobacco mosaic virus (TMV, Tomato mosaic virus (ToMV, belonging to pathotype P0 and Pepper mild mottle virus (PMMoV belonging to pathotype P1-2 respectively, that can infect sweet and hot peppers. Eighty-six genotypes of sweet and hot pepper were evaluated for the resistance to tobamovirus. Eigth genotypes of C. annuum, five

  12. Performance of an in-house human immunodeficiency virus type 1 genotyping system for assessment of drug resistance in Cuba.

    Science.gov (United States)

    Alemán, Yoan; Vinken, Lore; Kourí, Vivian; Pérez, Lissette; Álvarez, Alina; Abrahantes, Yeissel; Fonseca, Carlos; Pérez, Jorge; Correa, Consuelo; Soto, Yudira; Schrooten, Yoeri; Vandamme, Anne-Mieke; Van Laethem, Kristel

    2015-01-01

    As commercial human immunodeficiency virus type 1 drug resistance assays are expensive, they are not commonly used in resource-limited settings. Hence, a more affordable in-house procedure was set up taking into account the specific epidemiological and economic circumstances of Cuba. The performance characteristics of the in-house assay were evaluated using clinical samples with various subtypes and resistance patterns. The lower limit of amplification was determined on dilutions series of 20 clinical isolates and ranged from 84 to 529 RNA copies/mL. For the assessment of trueness, 14 clinical samples were analyzed and the ViroSeq HIV-1 Genotyping System v2.0 was used as the reference standard. The mean nucleotide sequence identity between the two assays was 98.7% ± 1.0. Additionally, 99.0% of the amino acids at drug resistance positions were identical. The sensitivity and specificity in detecting drug resistance mutations was respectively 94.1% and 99.5%. Only few discordances in drug resistance interpretation patterns were observed. The repeatability and reproducibility were evaluated using 10 clinical samples with 3 replicates per sample. The in-house test was very precise as nucleotide sequence identity among paired nucleotide sequences ranged from 98.7% to 99.9%. The acceptance criteria were met by the in-house test for all performance characteristics, demonstrating a high degree of accuracy. Subsequently, the applicability in routine clinical practice was evaluated on 380 plasma samples. The amplification success rate was 91% and good quality consensus sequences encoding the entire protease and the first 335 codons in reverse transcriptase could be obtained for 99% of the successful amplicons. The reagent cost per sample using the in-house procedure was around € 80 per genotyping attempt. Overall, the in-house assay provided good results, was feasible with equipment and reagents available in Cuba and was half as expensive as commercial assays.

  13. Genotyping and drug resistance patterns of Mycobacterium tuberculosis strains observed in a tuberculosis high-burden municipality in Northeast, Brazil

    Directory of Open Access Journals (Sweden)

    Roberta dos Santos Silva Luiz

    Full Text Available OBJECTIVES: This study has used a combination of clinical information, spoligotyping, and georeferencing system to elucidate the genetic diversity of the Mycobacterium tuberculosis isolates circulating in a TB-prevalent municipality of Northeast Brazil. METHODS: A total of 115 M. tuberculosis strains were isolated from pulmonary tuberculosis patients from January 2007 to March 2008 in Fortaleza. Drug susceptibility and spoligotyping assays were performed and place of residence of the patients were georeferenced. RESULTS: Of the M. tuberculosis strains studied, 51 (44.3% isolates were resistant to at least one drug (R-TB and 64 (55.7% were sensitive to all the drugs tested (S-TB. A high frequency of resistance was found in previously treated cases (84% and among new cases (16%; p < 0.001. a total of 74 (64% isolates were grouped into 22 spoligotyped lineages, while 41 (36% isolates were identified as new. among the predominant genotypes, 33% were latim american mediterranean (lam, 12% haarlem (h, and 5% u. there was no association of geographic distribution of rt-tb patients as compared to the controls and also the geographic location to the spoligotype patterns. the geospatial analysis revealed that 24 (23% patients (hot spot zones either shared the same residence or lived in a close neighborhood of a case. among these concentration zones, the patients lived in the same residence and shared a common genotype pattern and resistance pattern. DISCUSSION: it was observed that the spoligopatterns family distribution was similar to that reported for south america, prevailing the lam and h lineages. a high rate-case among the resistant TB group occurs as a result of transmitted and acquired resistance. A more effective surveillance program is needed in order to succeed in reducing tuberculosis in Northeast Brazil.

  14. Performance of an in-house human immunodeficiency virus type 1 genotyping system for assessment of drug resistance in Cuba.

    Directory of Open Access Journals (Sweden)

    Yoan Alemán

    Full Text Available As commercial human immunodeficiency virus type 1 drug resistance assays are expensive, they are not commonly used in resource-limited settings. Hence, a more affordable in-house procedure was set up taking into account the specific epidemiological and economic circumstances of Cuba. The performance characteristics of the in-house assay were evaluated using clinical samples with various subtypes and resistance patterns. The lower limit of amplification was determined on dilutions series of 20 clinical isolates and ranged from 84 to 529 RNA copies/mL. For the assessment of trueness, 14 clinical samples were analyzed and the ViroSeq HIV-1 Genotyping System v2.0 was used as the reference standard. The mean nucleotide sequence identity between the two assays was 98.7% ± 1.0. Additionally, 99.0% of the amino acids at drug resistance positions were identical. The sensitivity and specificity in detecting drug resistance mutations was respectively 94.1% and 99.5%. Only few discordances in drug resistance interpretation patterns were observed. The repeatability and reproducibility were evaluated using 10 clinical samples with 3 replicates per sample. The in-house test was very precise as nucleotide sequence identity among paired nucleotide sequences ranged from 98.7% to 99.9%. The acceptance criteria were met by the in-house test for all performance characteristics, demonstrating a high degree of accuracy. Subsequently, the applicability in routine clinical practice was evaluated on 380 plasma samples. The amplification success rate was 91% and good quality consensus sequences encoding the entire protease and the first 335 codons in reverse transcriptase could be obtained for 99% of the successful amplicons. The reagent cost per sample using the in-house procedure was around € 80 per genotyping attempt. Overall, the in-house assay provided good results, was feasible with equipment and reagents available in Cuba and was half as expensive as commercial

  15. Evaluation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples.

    Directory of Open Access Journals (Sweden)

    Devidas N Chaturbhuj

    Full Text Available OBJECTIVES: Validation of a cost effective in-house method for HIV-1 drug resistance genotyping using plasma samples. DESIGN: The validation includes the establishment of analytical performance characteristics such as accuracy, reproducibility, precision and sensitivity. METHODS: The accuracy was assessed by comparing 26 paired Virological Quality Assessment (VQA proficiency testing panel sequences generated by in-house and ViroSeq Genotyping System 2.0 (Celera Diagnostics, US as a gold standard. The reproducibility and precision were carried out on five samples with five replicates representing multiple HIV-1 subtypes (A, B, C and resistance patterns. The amplification sensitivity was evaluated on HIV-1 positive plasma samples (n = 88 with known viral loads ranges from 1000-1.8 million RNA copies/ml. RESULTS: Comparison of the nucleotide sequences generated by ViroSeq and in-house method showed 99.41±0.46 and 99.68±0.35% mean nucleotide and amino acid identity respectively. Out of 135 Stanford HIVdb listed HIV-1 drug resistance mutations, partial discordance was observed at 15 positions and complete discordance was absent. The reproducibility and precision study showed high nucleotide sequence identities i.e. 99.88±0.10 and 99.82±0.20 respectively. The in-house method showed 100% analytical sensitivity on the samples with HIV-1 viral load >1000 RNA copies/ml. The cost of running the in-house method is only 50% of that for ViroSeq method (112$ vs 300$, thus making it cost effective. CONCLUSIONS: The validated cost effective in-house method may be used to collect surveillance data on the emergence and transmission of HIV-1 drug resistance in resource limited countries. Moreover, the wide applications of a cost effective and validated in-house method for HIV-1 drug resistance testing will facilitate the decision making for the appropriate management of HIV infected patients.

  16. Genotype to phenotype, the molecular and physiological dimensions of resistance in arthropods

    NARCIS (Netherlands)

    Feyereisen, R.; Dermauw, W.; Van Leeuwen, T.

    2015-01-01

    The recent accumulation of molecular studies on mutations in insects, ticks and mites conferring resistance to insecticides, acaricides and biopesticides is reviewed. Resistance is traditionally classified by physiological and biochemical criteria, such as target-site insensitivity and metabolic res

  17. Genotypic Detection of Antibiotic Resistance in "Escherichia Coli.": A Classroom Exercise

    Science.gov (United States)

    Longtin, Sarah; Guilfoile, Patrick; Asper, Andrea

    2004-01-01

    Bacterial antibiotic resistance remains a problem of clinical importance. Current microbiological methods for determining antibiotic resistance are based on culturing bacteria, and may require up to 48 hours to complete. Molecular methods are increasingly being developed to speed the identification of antibiotic resistance and to determine its…

  18. Resistência de genótipos de feijoeiro a Bemisia tabaci biótipo B Resistance of bean genotypes to Bemisia tabaci biotype B

    Directory of Open Access Journals (Sweden)

    Lucas Castro Torres

    2012-01-01

    Full Text Available O estudo de genótipos de feijoeiro resistentes à mosca-branca Bemisia tabaci (Genn. biótipo B (Hemiptera: Aleyrodidae é de grande importância devido aos danos ocasionados por essa praga à cultura. Neste trabalho, foram estudados a atratividade para adultos, a preferência para oviposição em testes com e sem chance de escolha, o ciclo ovo-adulto e o tipo e número de tricomas presentes nos folíolos. Os experimentos foram realizados em casa de vegetação avaliando-se, inicialmente, cem genótipos de feijoeiro. A resistência do tipo não-preferência para alimentação e/ou antibiose foi observada nos genótipos ARC-3, IAC-Alvorada e Canário 101, sendo a emergência de adultos fortemente influenciada pelos genótipos. Também se observou correlação negativa moderada entre o número de ovos e o número de tricomas glandulares, e correlação positiva muito forte entre o número de ovos e o número de tricomas tectores unciformes.The study of bean genotypes resistant to the whitefly Bemisia tabaci (Genn. B biotype (Hemiptera: Aleyrodidae has been of great importance due to the damage caused by this pest. In this research, bean genotypes were evaluated regarding attractiveness to whitefly adults, the preference for oviposition in free-choice and non choice tests, egg-to-adult development time and characterized for the presence, type and number of trichomes. The experiments were carried out under greenhouse conditions initially evaluating 100 bean genotypes. The non-preference type of resistance for feeding and/or antibiosis was observed in the genotypes ARC-3, IAC-Alvorada and Canário 101, and the emergence of adults was strongly influenced by the genotypes. It was also observed a moderate negative correlation between the number of eggs and the number of glandular trichomes, as well as a very strong positive correlation between the number of eggs and the number of unciform non-glandular trichomes.

  19. Plasmodium falciparum genotypes associated with chloroquine and amodiaquine resistance in Guinea-Bissau

    DEFF Research Database (Denmark)

    Ursing, Johan; Kofoed, Poul-Erik; Rodrigues, Amabelia

    2007-01-01

    Chloroquine is the most commonly used antimalarial in Guinea-Bissau and high doses are routinely prescribed. Blood from 497 patients treated with different doses of chloroquine or amodiaquine were genotyped. Pfcrt and pfmdr1 polymorphisms were identified. Pfmsp2 analysis identified recrudescent i...

  20. Phenotypic and genotypic characterization of multidrug-resistant Bacteroides, Parabacteroides spp., and Pseudoflavonifractor from a Costa Rican hospital.

    Science.gov (United States)

    Molina, José; Barrantes, Gloriana; Quesada-Gómez, Carlos; Rodríguez, César; Rodríguez-Cavallini, Evelyn

    2014-10-01

    Multidrug resistance in Bacteroides spp. and related genera is uncommon and has not been described in Latin America until now. We studied phenotypically and genotypically the multidrug resistance of 10 clinical strains of Bacteroides, two of Parabacteroides distasonis, and one of Pseudoflavonifractor capillosus recovered in a national hospital between 2006 and 2010. To this end, we determined minimum inhibitory concentrations (MICs) of amoxicillin, amoxicillin-clavulanic acid, cefotaxime, imipenem, clindamycin, ciprofloxacin, tetracycline, and metronidazole using E-tests, evaluated the isolates for β-lactamases with nitrocefin hydrolysis tests, performed a polymerase chain reaction (PCR)-based screening of erm, tet, and nim genes, obtained partial gyrA sequences, and studied the effect of tazobactam and efflux pump inhibitors (EPI) on the MIC of cefotaxime, clindamycin, and ciprofloxacin. Three isolates were resistant to four different classes of antibiotics and 10 were resistant to three. β-lactam resistance was in most cases due to β-lactamases susceptible of partial inhibition by tazobactam. Ten isolates were cfxA-positive and two isolates had cepA. Twelve isolates were highly resistant to clindamycin and nine were highly resistant to ciprofloxacin. However, these phenotypes were not linked to ermA, ermB, ermF, and ermG or mutations in gyrA. Addition of EPI lowered the MICs of clindamycin and ciprofloxacin of one and four isolates, respectively. Twelve isolates had tetQ and four were positive for tetM. In both cases, genes of the two-component system RteAB accompanied tet genes. Although metronidazole susceptibility was universal, nim genes were not present. To our knowledge, this is the first report of multidrug resistance due to less commonly identified or alternative mechanisms in strains of Bacteroides and related species from a developing country.

  1. Rapid and sensitive detection of fluoroquinolone-resistant Escherichia coli from urine samples using a genotyping DNA microarray.

    Science.gov (United States)

    Yu, Xiaolei; Susa, Milorad; Weile, Jan; Knabbe, Cornelius; Schmid, Rolf D; Bachmann, Till T

    2007-10-01

    Urinary tract infections (UTI) are among the most common bacterial infections in humans, with Escherichia coli being the major cause of infection. Fluoroquinolone resistance of uropathogenic E. coli has increased significantly over the last decade. In this study a microarray-based assay was developed and applied, which provides a rapid, sensitive and specific detection of fluoroquinolone-resistant E. coli in urine. The capture probes were designed against previously identified and described hotspots for quinolone resistance (codons 83 and 87 of gyrA). The key goals of this development were to reduce assay time while increasing the sensitivity and specificity as compared with a pilot version of a gyrA genotyping DNA microarray. The performance of the assay was demonstrated with pure cultures of 30 E. coli isolates as well as with urine samples spiked with 6 E. coli isolates. The microarray results were confirmed by standard DNA sequencing and were in full agreement with the phenotypic antimicrobial susceptibility testing using standard methods. The DNA microarray test displayed an assay time of 3.5h, a sensitivity of 100CFU/ml, and the ability to detect fluoroquinolone-resistant E. coli in the presence of a 10-fold excess of fluoroquinolone-susceptible E. coli cells. As a consequence, we believe that this microarray-based determination of antibiotics resistance has a true potential for the application in clinical routine laboratories in the future.

  2. Genotyping of chloroquine resistant Plasmodium falciparum in wild caught Anopheles minimus mosquitoes in a malaria endemic area of Assam, India.

    Science.gov (United States)

    Sarma, D K; Mohapatra, P K; Bhattacharyya, D R; Mahanta, J; Prakash, A

    2014-09-01

    We validated the feasibility of using Plasmodium falciparum, the human malaria parasite, DNA present in wild caught vector mosquitoes for the characterization of chloroquine resistance status. House frequenting mosquitoes belonging to Anopheles minimus complex were collected from human dwellings in a malaria endemic area of Assam, Northeast India and DNA was extracted from the head-thorax region of individual mosquitoes. Anopheles minimus complex mosquitoes were identified to species level and screened for the presence of Plasmodium sp. using molecular tools. Nested PCR-RFLP method was used for genotyping of P. falciparum based on K76T mutation in the chloroquine resistance transporter (pfcrt) gene. Three of the 27 wild caught An. minimus mosquitoes were harbouring P. falciparum sporozoites (positivity 11.1%) and all 3 were had 76T mutation in the pfcrt gene, indicating chloroquine resistance. The approach of characterizing antimalarial resistance of malaria parasite in vector mosquitoes can potentially be used as a surveillance tool for monitoring transmission of antimalarial drug resistant parasite strains in the community.

  3. Adaptive Laboratory Evolution of Antibiotic Resistance Using Different Selection Regimes Lead to Similar Phenotypes and Genotypes

    DEFF Research Database (Denmark)

    Jahn, Leonie Johanna; Munck, Christian; Ellabaan, Mostafa M Hashim

    2017-01-01

    Antibiotic resistance is a global threat to human health, wherefore it is crucial to study the mechanisms of antibiotic resistance as well as its emergence and dissemination. One way to analyze the acquisition of de novo mutations conferring antibiotic resistance is adaptive laboratory evolution....... However, various evolution methods exist that utilize different population sizes, selection strengths, and bottlenecks. While evolution in increasing drug gradients guarantees high-level antibiotic resistance promising to identify the most potent resistance conferring mutations, other selection regimes...... compare the geno- and phenotypes of Escherichia coli after evolution to Amikacin, Piperacillin, and Tetracycline under four different selection regimes. Interestingly, key mutations that confer antibiotic resistance as well as phenotypic changes like collateral sensitivity and cross-resistance emerge...

  4. Evaluation of Mungbean Genotypes Based on Yield Stability and Reaction to Mungbean Yellow Mosaic Virus Disease

    OpenAIRE

    AKM Mahbubul Alam; Prakit Somta; Choosak Jompuk; Prasert Chatwachirawong; Peerasak Srinives

    2014-01-01

    This work was conducted to identify mungbean genotypes showing yield stability and resistance to mungbean yellow mosaic virus (MYMV) disease. Sixteen genotypes were evaluated in a randomized complete block design with two replications for two years (2011 and 2012) at three locations (Gazipur, Ishurdi and Madaripur) of the Bangladesh Agricultural Research Institute. An analysis of variance exhibited significant effects of genotype (G), environment (E), and genotype × environment (G×E) on grain...

  5. Genetic Diversity and Selective Pressure in Hepatitis C Virus Genotypes 1–6: Significance for Direct-Acting Antiviral Treatment and Drug Resistance

    Science.gov (United States)

    Cuypers, Lize; Li, Guangdi; Libin, Pieter; Piampongsant, Supinya; Vandamme, Anne-Mieke; Theys, Kristof

    2015-01-01

    Treatment with pan-genotypic direct-acting antivirals, targeting different viral proteins, is the best option for clearing hepatitis C virus (HCV) infection in chronically infected patients. However, the diversity of the HCV genome is a major obstacle for the development of antiviral drugs, vaccines, and genotyping assays. In this large-scale analysis, genome-wide diversity and selective pressure was mapped, focusing on positions important for treatment, drug resistance, and resistance testing. A dataset of 1415 full-genome sequences, including genotypes 1–6 from the Los Alamos database, was analyzed. In 44% of all full-genome positions, the consensus amino acid was different for at least one genotype. Focusing on positions sharing the same consensus amino acid in all genotypes revealed that only 15% was defined as pan-genotypic highly conserved (≥99% amino acid identity) and an additional 24% as pan-genotypic conserved (≥95%). Despite its large genetic diversity, across all genotypes, codon positions were rarely identified to be positively selected (0.23%–0.46%) and predominantly found to be under negative selective pressure, suggesting mainly neutral evolution. For NS3, NS5A, and NS5B, respectively, 40% (6/15), 33% (3/9), and 14% (2/14) of the resistance-related positions harbored as consensus the amino acid variant related to resistance, potentially impeding treatment. For example, the NS3 variant 80K, conferring resistance to simeprevir used for treatment of HCV1 infected patients, was present in 39.3% of the HCV1a strains and 0.25% of HCV1b strains. Both NS5A variants 28M and 30S, known to be associated with resistance to the pan-genotypic drug daclatasvir, were found in a significant proportion of HCV4 strains (10.7%). NS5B variant 556G, known to confer resistance to non-nucleoside inhibitor dasabuvir, was observed in 8.4% of the HCV1b strains. Given the large HCV genetic diversity, sequencing efforts for resistance testing purposes may need to be

  6. Genetic Diversity and Selective Pressure in Hepatitis C Virus Genotypes 1–6: Significance for Direct-Acting Antiviral Treatment and Drug Resistance

    Directory of Open Access Journals (Sweden)

    Lize Cuypers

    2015-09-01

    Full Text Available Treatment with pan-genotypic direct-acting antivirals, targeting different viral proteins, is the best option for clearing hepatitis C virus (HCV infection in chronically infected patients. However, the diversity of the HCV genome is a major obstacle for the development of antiviral drugs, vaccines, and genotyping assays. In this large-scale analysis, genome-wide diversity and selective pressure was mapped, focusing on positions important for treatment, drug resistance, and resistance testing. A dataset of 1415 full-genome sequences, including genotypes 1–6 from the Los Alamos database, was analyzed. In 44% of all full-genome positions, the consensus amino acid was different for at least one genotype. Focusing on positions sharing the same consensus amino acid in all genotypes revealed that only 15% was defined as pan-genotypic highly conserved (≥99% amino acid identity and an additional 24% as pan-genotypic conserved (≥95%. Despite its large genetic diversity, across all genotypes, codon positions were rarely identified to be positively selected (0.23%–0.46% and predominantly found to be under negative selective pressure, suggesting mainly neutral evolution. For NS3, NS5A, and NS5B, respectively, 40% (6/15, 33% (3/9, and 14% (2/14 of the resistance-related positions harbored as consensus the amino acid variant related to resistance, potentially impeding treatment. For example, the NS3 variant 80K, conferring resistance to simeprevir used for treatment of HCV1 infected patients, was present in 39.3% of the HCV1a strains and 0.25% of HCV1b strains. Both NS5A variants 28M and 30S, known to be associated with resistance to the pan-genotypic drug daclatasvir, were found in a significant proportion of HCV4 strains (10.7%. NS5B variant 556G, known to confer resistance to non-nucleoside inhibitor dasabuvir, was observed in 8.4% of the HCV1b strains. Given the large HCV genetic diversity, sequencing efforts for resistance testing purposes may

  7. Genetic diversity of Mycobacterium tuberculosis from Guadalajara, Mexico and identification of a rare multidrug resistant Beijing genotype.

    Science.gov (United States)

    Flores-Treviño, Samantha; Morfín-Otero, Rayo; Rodríguez-Noriega, Eduardo; González-Díaz, Esteban; Pérez-Gómez, Héctor R; Bocanegra-García, Virgilio; Vera-Cabrera, Lucio; Garza-González, Elvira

    2015-01-01

    Determining the genetic diversity of M. tuberculosis strains allows identification of the distinct Mycobacterium tuberculosis genotypes responsible for tuberculosis in different regions. Several studies have reported the genetic diversity of M. tuberculosis strains in Mexico, but little information is available from the state of Jalisco. Therefore, the aim of this study was to determine the genetic diversity of Mycobacterium tuberculosis clinical isolates from Western Mexico. Sixty-eight M. tuberculosis isolates were tested for susceptibility to first-line drugs using manual Mycobacteria Growth Indicator Tube method and genotyped using spoligotyping and IS6110-restriction fragment length polymorphism (RFLP) pattern analyses. Forty-seven (69.1%) isolates were grouped into 10 clusters and 21 isolates displayed single patterns by spoligotyping. Three of the 21 single patterns corresponded to orphan patterns in the SITVITWEB database, and 1 new type that contained 2 isolates was created. The most prevalent lineages were T (38.2%), Haarlem (17.7%), LAM (17.7%), X (7.4%), S (5.9%), EAI (1.5%) and Beijing (1.5%). Six (12.8%) of the clustered isolates were MDR, and type 406 of the Beijing family was among the MDR isolates. Seventeen (26.2%) isolates were grouped into 8 clusters and 48 isolates displayed single patterns by IS6110-RFLP. Combination of IS6110-RFLP and spoligotyping reduced the clustering rate to 20.0%. The results show that T, Haarlem, and LAM are predominant lineages among clinical isolates of M. tuberculosis in Guadalajara, Mexico. Clustering rates indicated low transmission of MDR strains. We detected a rare Beijing genotype, SIT406, which was a highly resistant strain. This is the first report of this Beijing genotype in Latin America.

  8. Tomato resistance to Alternaria stem canker : localization in host genotypes and functional expression compared to non-host resistance

    NARCIS (Netherlands)

    Witsenboer, H.M.A.; Griend, E.G. van de; Tiersma, J.B.; Nijkamp, H.J.J.; Hille, J.

    1989-01-01

    The Alternaria stem canker resistance locus (Asc-locus), involved in resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici and in insensitivity to host-specific toxins (AAL-toxins) produced by the pathogen, was genetically mapped on the tomato genome. Susceptibility and resistanc

  9. Evaluation of chickpea genotypes for resistance to Ascochyta blight (Ascochyta rabiei disease in the dry highlands of Kenya

    Directory of Open Access Journals (Sweden)

    Paul K. KIMURTO

    2013-05-01

    Full Text Available Chickpea (Cicer arietinum is an edible legume grown widely for its nutritious seed, which is rich in protein, minerals, vitamins and dietary fibre. It’s a new crop in Kenya whose potential has not been utilized fully due to abiotic and biotic stresses that limit its productivity. The crop is affected mainly by Ascochyta blight (AB which is widespread in cool dry highlands causing up to 100% yield loss. The objective of this study was to evalu- ate the resistance of selected chickpea genotypes to AB in dry highlands of Kenya. The study was done in 2 sites (Egerton University-Njoro and Agricultural Training centre-ATC-Koibatek for one season during long rains of 2010/2011 growing season. Thirty six genotypes from reference sets and mini-core samples introduced from ICR- SAT were evaluated. There were significant (P<0.001 differences in AB responses and grain yield performance in test genotypes in both sites. AB was more severe at Egerton-Njoro (mean score 5.7 than ATC-Koibatek (mean score 4.25, with subsequent low grain yield. Genotypes ICC7052, ICC4463, ICC4363, ICC2884, ICC7150, ICC15294 and ICC11627 had both highest grain yield in decreasing order (mean range 1790-1053 Kg ha-1 and best resist- ance to AB. Further evaluation is needed in other multi-locations and their use in breeding program determined especially because of their undesirable black seed color. Commercial varieties (LDT068, LDT065, Chania desi 1, and Saina K1 were all susceptible to AB, but with grain yield >1200 Kg ha-1. The findings of the study showed that chickpea should be sown during the short rains (summer in the dry highlands of Kenya when conditions are drier and warmer and less favorable for AB infection. However yield could be increased by shifting the sowing date from dry season to long rain (winter thus avoiding terminal drought if AB resistant cultivars with acceptable agronomic traits could be identified.

  10. QTL analysis of the spring wheat "Chapio" identifies stable stripe rust resistance despite inter-continental genotype × environment interactions.

    Science.gov (United States)

    Yang, E-N; Rosewarne, G M; Herrera-Foessel, S A; Huerta-Espino, J; Tang, Z-X; Sun, C-F; Ren, Z-L; Singh, R P

    2013-07-01

    Chapio is a spring wheat developed by CIMMYT in Mexico by a breeding program that focused on multigenic resistances to leaf rust and stripe rust. A population consisting of 277 recombinant inbred lines (RILs) was developed by crossing Chapio with Avocet. The RILs were genotyped with DArT markers (137 randomly selected RILs) and bulked segregant analysis conducted to supplement the map with informative SSR markers. The final map consisted of 264 markers. Phenotyping against stripe rust was conducted for three seasons in Toluca, Mexico and at three sites over two seasons (total of four environments) in Sichuan Province, China. Significant loci across the two inter-continental regions included Lr34/Yr18 on 7DS, Sr2/Yr30 on 3BS, and a QTL on 3D. There were significant genotype × environment interactions with resistance gene Yr31 on 2BS being effective in most of the Toluca environments; however, a late incursion of a virulent pathotype in 2009 rendered this gene ineffective. This locus also had no effect in China. Conversely, a 5BL locus was only effective in the Chinese environments. There were also complex additive interactions. In the Mexican environments, Yr31 suppressed the additive effect of Yr30 and the 3D locus, but not of Lr34/Yr18, while in China, the 3D and 5BL loci were generally not additive with each other, but were additive when combined with other loci. These results indicate the importance of maintaining diverse, multi-genic resistances as Chapio had stable inter-continental resistance despite the fact that there were QTLs that were not effective in either one or the other region.

  11. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai.

    Science.gov (United States)

    Xu, Jie; Shi, Chunlei; Song, Minghui; Xu, Xuebin; Yang, Puyu; Paoli, George; Shi, Xianming

    2014-04-01

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus, between food products and humans has become a serious problem. Hence, it is necessary to monitor S. aureus through the food supply chain. In this study, the disk diffusion method and epsilometer test were performed to determine the prevalence of ARSA in 78 foodborne isolates using 18 antibiotics. The highest resistance frequency was found for penicillin G (74.4%), followed by erythromycin (59.0%) and clindamycin (44.9%), whereas no vancomycin-resistant isolates were found. The 78 isolates could be subtyped into 31 resistance profiles and 11 clusters based on their antimicrobial susceptibility. Furthermore, Polymerase chain reaction (PCR) screening for the presence of 13 genes conferring antibiotic resistance was conducted. The presence of resistance genes was relatively high: blaTEM (80.8%), ermB (41.0%), grlA (38.5%), ermC (35.9%), and aac6'/aph2" (35.9%). The incidence of antibiotic resistance was significantly correlated to food types (p = 0.018), with isolates from meat and raw milk more resistant to antibiotics than those from frozen food and vegetables.

  12. Performance assessment of the GenoType MTBDRsl test and DNA sequencing for detection of second-line and ethambutol drug resistance among patients infected with multidrug-resistant Mycobacterium tuberculosis.

    Science.gov (United States)

    Huang, Wei-Lun; Chi, Ting-Lin; Wu, Mei-Hua; Jou, Ruwen

    2011-07-01

    The GenoType MTBDRsl test and DNA sequencing were used to rapidly detect second-line drug- and ethambutol (EMB)-resistant Mycobacterium tuberculosis. The ability of these two assays to detect the presence of mutations associated with resistance to fluoroquinolones (FLQ), aminoglycosides/cyclic peptide (AG/CP), and EMB in the gyrA, rrs, and embB genes (for the GenoType MTBDRsl test) and gyrA, gyrB, rrs, eis, embC, embA, embB, and embR genes (for DNA sequencing) was compared to that of conventional agar proportion drug susceptibility testing (DST). We evaluated 234 multidrug-resistant (MDR) M. tuberculosis isolates. The two molecular methods had high levels of specificity (95.8 to 100%). The sensitivities for FLQ resistance detection for both methods were 85.1%. For AG (kanamycin [KM] and amikacin [AM]) and CP (capreomycin CAP]), the sensitivities of resistance detection using the GenoType MTBDRsl test were 43.2%, 84.2%, and 71.4%, respectively, while with the inclusion of an extra gene, eis, in sequencing, the sensitivity reached 70.3% for detection of KM resistance. The sensitivities of EMB resistance detection were 56.2% and 90.7% with the GenoType MTBDRsl test and sequencing, respectively. We found that the GenoType MTBDRsl test can rapidly detect resistance to FLQ, CAP, and AM. The accuracy of the GenoType MTBDRsl test for the detection of FLQ and AM resistance was comparable to that of conventional DST; however, the test was less accurate for the detection of KM and EMB resistance and demonstrated a poor predictive value for CAP resistance. We recommend including new alleles consisting of the eis promoter and embB genes in molecular analysis. However, conventional DST is necessary to rule out false-negative results from molecular assays.

  13. Resistência de genótipos de tomateiro ao ácaro rajado Resistance of tomato genotypes to spider mite

    Directory of Open Access Journals (Sweden)

    Wilson Itamar Maruyama

    2002-09-01

    Full Text Available Avaliou-se a resistência de genótipos de tomateiro selvagens [Lycopersicon pennellii (LA 716, L. hirsutum var. glabratum (PI 126449, PI 134417, L. hirsutum (PI 127826, PI 127827, L. peruvianum (CGO 6707, L. peruvianum var. dentatum (WYR 2020, LA 111, L. peruvianum var. glandulosum (LA 1113-1, LA 1113-2] e comerciais [(L. esculentum Gem Pride, Santa Clara, e híbridos Bruna VFN, Carmem, Fortaleza, Débora Plus VFN] ao ácaro rajado (Tetranychus urticae. O número médio de ovos, fases imaturas (larvas, protoninfas e deutoninfas e adultos por folíolo foi contado; o índice de preferência para oviposição (IPO foi calculado. O delineamento experimental foi blocos ao acaso, com 6 repetições. Os genótipos LA 716, PI 126449, PI 134417, PI 127827, PI 127826 e Gem Pride apresentaram não-preferência para oviposição do ácaro rajado, sendo deterrentes quanto à classificação do IPO, enquanto os genótipos LA 111, WYR 2020, LA 1113-2 e LA1113-1 foram os mais preferidos para a oviposição e foram considerados como estimulantes pelo IPO.The resistance of different tomato genotypes to spider mite (Tetranychus urticae was evaluated. The wild genotypes evaluated were Lycopersicon pennellii (LA 716, L. hirsutum f. glabratum (PI 126449, PI 134417, L. hirsutum (PI 127826, PI 127827, L. peruvianum (CGO 6707, L. peruvianum f. dentatum (WYR 2020, LA 111, L. peruvianum f. glandulosum (LA 1113-1, LA 1113-2; and the commercial genotypes (L. esculentum were Gem Pride, Santa Clara, and the F1 hybrids Bruna VFN, Carmem, Fortaleza and Débora Plus VFN. The number of eggs was counted, young phases (larvae, protonimphs, deutonimphs and adults per leafleft. After the counting, the index of oviposition preference (IOP also was calculated. The experiment was realized in randomized block design, with six replications. The LA 716, PI 126449, PI 134417, PI 127827, PI 127826 and Gem Pride genotypes showed non-preference for spider mite oviposition, being deterrents

  14. Phenotypes and Genotypes of Erythromycin-Resistant Streptococcus pyogenes Strains in Italy and Heterogeneity of Inducibly Resistant Strains

    OpenAIRE

    Giovanetti, Eleonora; Montanari, Maria Pia; Mingoia, Marina; Varaldo, Pietro Emanuele

    1999-01-01

    A total of 387 clinical strains of erythromycin-resistant (MIC, ≥1 μg/ml) Streptococcus pyogenes, all isolated in Italian laboratories from 1995 to 1998, were examined. By the erythromycin-clindamycin double-disk test, 203 (52.5%) strains were assigned to the recently described M phenotype, 120 (31.0%) were assigned to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLS) phenotype, and 64 (16.5%) were assigned to the constitutive MLS resistance (cMLS) phenotype. The ind...

  15. Consequences of noncompliance for therapy efficacy and emergence of resistance in murine tuberculosis caused by the Beijing genotype of Mycobacterium tuberculosis.

    Science.gov (United States)

    de Steenwinkel, Jurriaan E M; ten Kate, Marian T; de Knegt, Gerjo J; Verbrugh, Henri A; Aarnoutse, Rob E; Boeree, Martin J; den Bakker, Michael A; van Soolingen, Dick; Bakker-Woudenberg, Irma A J M

    2012-09-01

    Despite great effort by health organizations worldwide in fighting tuberculosis (TB), morbidity and mortality are not declining as expected. One of the reasons is related to the evolutionary development of Mycobacterium tuberculosis, in particular the Beijing genotype strains. In a previous study, we showed the association between the Beijing genotype and an increased mutation frequency for rifampin resistance. In this study, we use a Beijing genotype strain and an East-African/Indian genotype strain to investigate with our mouse TB model whether the higher mutation frequency observed in a Beijing genotype strain is associated with treatment failure particularly during noncompliance therapy. Both genotype strains showed high virulence in comparison to that of M. tuberculosis strain H37Rv, resulting in a highly progressive infection with a rapid lethal outcome in untreated mice. Compliance treatment was effective without relapse of TB irrespective of the infecting strain, showing similar decreases in the mycobacterial load in infected organs and similar histopathological changes. Noncompliance treatment, simulated by a reduced duration and dosing frequency, resulted in a relapse of infection. Relapse rates were correlated with the level of noncompliance and were identical for Beijing infection and East African/Indian infection. However, only in Beijing-infected mice, isoniazid-resistant mutants were selected at the highest level of noncompliance. This is in line with the substantial selection of isoniazid-resistant mutants in vitro in a wide isoniazid concentration window observed for the Beijing strain and not for the EAI strain. These results suggest that genotype diversity of M. tuberculosis may be involved in emergence of resistance and indicates that genotype-tailor-made treatment should be investigated.

  16. Genotypic and phenotypic virulence characteristics and antimicrobial resistance of Yersinia spp. isolated from meat and milk products.

    Science.gov (United States)

    Özdemir, Fatma; Arslan, Seza

    2015-06-01

    A total of 300 food samples including 180 milk and 120 meat products have been examined for the presence of Yersinia spp. using the ISO 10273 and the cold enrichment method. The overall prevalence of Yersinia spp. was 84 (28%). Yersinia enterocolitica was isolated from 18 (6%) of the 300 samples. The other Yersinia species were detected in the samples Yersinia rohdei 15 (5%), Yersinia intermedia 14 (4.7%), Yersinia pseudotuberculosis 12 (4%), Yersinia ruckeri 12 (4%), Yersinia mollaretii 5 (1.7%), Yersinia bercovieri 4 (1.3%), and atypical Yersinia spp. 4 (1.3%). The conventionally identified Y. enterocolitica strains were also confirmed by the 16S rRNA gene sequencing. All Y. enterocolitica strains biotyped as 1A had negative results in the phenotypic virulence tests. The 84 Yersinia strains were also examined genotypically for the presence of virulence genes. None of the Y. enterocolitica and other Yersinia strains contained the ail, ystA, yadA, and virF except only 1 Y. intermedia and 2 Y. enterocolitica strains that were found to be positive for ystB. Antimicrobial resistance of 84 Yersinia to 16 antimicrobial agents was determined by the disk diffusion method. All strains were sensitive to tobramycine and imipenem while resistant to clindamycin. Although 84.5% of the strains were resistant to at least 3 or more antimicrobial agents, 64.3% of them were resistant to 4 or more antimicrobial agents. © 2015 Institute of Food Technologists®

  17. Responsiveness of different citrus genotypes to the Xanthomonas citri ssp. citri-derived pathogen-associated molecular pattern (PAMP) flg22 correlates with resistance to citrus canker.

    Science.gov (United States)

    Shi, Qingchun; Febres, Vicente J; Jones, Jeffrey B; Moore, Gloria A

    2015-06-01

    The bacterial agent of citrus canker disease (Xanthomonas citri ssp. citri, Xcc) has caused tremendous economic losses to the citrus industry around the world. Pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) is important to plant immunity. In this study, we compared the defence responses of citrus canker-resistant and citrus canker-susceptible genotypes to the Xcc-derived PAMP flg22 (Xflg22) by analysing the expression of 20 citrus defence-associated genes. We showed that, in the most resistant genotype, 'Nagami' kumquat, there was significant induction of several defence genes (EDS1, NDR1, PBS1, RAR1, SGT1, PAL1, NPR2 and NPR3) as early as 6 h and up to 72 h after Xflg22 treatment. At the other end of the spectrum, highly susceptible 'Duncan' grapefruit showed no induction of the same defence genes, even 120 h after treatment. Citrus genotypes with partial levels of resistance showed intermediate levels of transcriptional reprogramming that correlated with their resistance level. Xflg22 also triggered a rapid oxidative burst in all genotypes which was higher and accompanied by the induction of PTI marker genes (WRKY22 and GST1) only in the more resistant genotypes. Pretreatment with Xflg22 prior to Xcc inoculation inhibited bacterial growth in kumquat, but not in grapefruit. A flagellin-deficient Xcc strain (XccΔfliC) showed greater growth increase relative to wild-type Xcc in kumquat than in grapefruit. Taken together, our results indicate that Xflg22 initiates strong PTI in canker-resistant genotypes, but not in susceptible ones, and that a robust induction of PTI is an important component of citrus resistance to canker.

  18. Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

    Science.gov (United States)

    Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

  19. Genotypic and phenotypic characterization of methicillin-resistant Staphylococcus aureus (MRSA) clones with high-level mupirocin resistance.

    Science.gov (United States)

    González-Domínguez, María; Seral, Cristina; Potel, Carmen; Sáenz, Yolanda; Álvarez, Maximiliano; Torres, Carmen; Castillo, Francisco Javier

    2016-06-01

    A high proportion of methicillin-resistant Staphylococcus aureus isolates recovered in one year period showed high-level mupirocin-resistance (HLMUPR-MRSA) in our environment (27.2%). HLMUPR-MRSA isolates were mainly collected from skin and soft tissue samples, and diabetes was the main related comorbidity condition. These isolates were more frequently found in vascular surgery. HLMUPR-MRSA was more resistant to aminoglycosides than mupirocin-susceptible MRSA, linked to the presence of bifunctional and/or nucleotidyltransferase enzymes with/without macrolide resistance associated with the msr(A) gene. Most of HLMUPR-MRSA isolates belonged to ST125/t067. Nine IS257-ileS2 amplification patterns (p3 was the most frequent) were observed in HLMUPR-MRSA isolates, suggesting the presence of several mupirocin-resistance-carrying plasmids in our environment and promoting the emergence of mupirocin resistance. The presence of the same IS257-ileS2 amplification pattern p3 in 65% of HLMUPR-MRSA, all of them ST125/t067, suggests a clonal spread in our hospital and community environment which could explain the high prevalence of HLMUPR-MRSA during the study period. An outbreak situation or an increase in mupirocin consumption was not observed.

  20. Low level genotypic chloroquine resistance near Malawi's northern border with Tanzania.

    Science.gov (United States)

    Bridges, Daniel J; Molyneux, Malcolm; Nkhoma, Standwell

    2009-09-01

    We conducted a prevalence study of mutations in Plasmodium falciparum that are associated with antimalarial drug resistance at a rural site in Karonga near Malawi's northern border with Tanzania. We found a higher prevalence of the key chloroquine resistance-conferring mutation in the pfcrt gene (K76T) at this site in comparison with the prevalence in Blantyre, a city in the south of Malawi, far from an international border (9%vs. 0%; P Malawi was recently reported to be over 50%. Our findings suggest a considerable 'leakage' of parasite antimalarial drug resistance across the border between two countries with different national malaria control policies and with different levels of resistance. Neighbouring countries should consider implementing common regional rather than national malaria treatment policies to prevent the spread of antimalarial drug resistance alleles across their borders.

  1. Phenotypes, genotypes, serotypes and molecular epidemiology of erythromycin-resistant Streptococcus agalactiae in Italy.

    Science.gov (United States)

    De Francesco, M A; Caracciolo, S; Gargiulo, F; Manca, N

    2012-08-01

    The purpose of this investigation was to analyse Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected in Italy from vaginal and urine samples in respect to their clonality, distribution of virulence factors and antimicrobial resistance determinants. Three hundred and eighty-eight GBS were recovered from clinical samples. They were analysed for antibiotic resistance profiling. Erythromycin-resistant strains were further characterised by multilocus sequence typing (MLST), serotyping and the detection of alp genes of the alpha-like protein (Alp) family. GBS isolates represented 40 different sequence types (STs), grouped in five clonal complexes (CCs) and belonged to seven serotypes. Most serotype V strains (81%) possessed alp2-3; serotype Ia carried mainly epsilon, while the serotype III mainly rib. All isolates were susceptible to penicillin, whereas resistance to erythromycin was detected in 15% of isolates. Most erythromycin-resistant GBS strains were of serotype V (56.8%) and belonged to the CC-1 group (50%). Macrolide resistance phenotypes were the cMLS(B) (46.5%) and the M phenotypes (46.5%) due to the presence of ermB and mefA/E genes, respectively. These results provide data which establish a baseline for monitoring erythromycin resistance in this region and also provide an insight into the correlation among clonal types, serotypes, surface protein and resistance genes. The increased prevalence of strains that displayed the M phenotype strengthens the importance of the epidemiological surveillance of macrolide resistance in GBS, which may also represent an important reservoir of resistance genes for other species.

  2. Antibiotic resistance and genotype of beta-lactamase producing Escherichia coli in nosocomial infections in Cotonou, Benin.

    Science.gov (United States)

    Anago, Eugénie; Ayi-Fanou, Lucie; Akpovi, Casimir D; Hounkpe, Wilfried B; Agassounon-Djikpo Tchibozo, Micheline; Bankole, Honoré S; Sanni, Ambaliou

    2015-01-17

    Beta lactams are the most commonly used group of antimicrobials worldwide. The presence of extended-spectrum lactamases (ESBL) affects significantly the treatment of infections due to multidrug resistant strains of gram-negative bacilli. The aim of this study was to characterize the beta-lactamase resistance genes in Escherichia coli isolated from nosocomial infections in Cotonou, Benin. Escherichia coli strains were isolated from various biological samples such as urine, pus, vaginal swab, sperm, blood, spinal fluid and catheter. Isolated bacteria were submitted to eleven usual antibiotics, using disc diffusion method according to NCCLS criteria, for resistance analysis. Beta-lactamase production was determined by an acidimetric method with benzylpenicillin. Microbiological characterization of ESBL enzymes was done by double disc synergy test and the resistance genes TEM and SHV were screened by specific PCR. ESBL phenotype was detected in 29 isolates (35.5%). The most active antibiotic was imipenem (96.4% as susceptibility rate) followed by ceftriaxone (58.3%) and gentamicin (54.8%). High resistance rates were observed with amoxicillin (92.8%), ampicillin (94%) and trimethoprim/sulfamethoxazole (85.7%). The genotype TEM was predominant in ESBL and non ESBL isolates with respectively 72.4% and 80%. SHV-type beta-lactamase genes occurred in 24.1% ESBL strains and in 18.1% of non ESBL isolates. This study revealed the presence of ESBL producing Eschericiha coli in Cotonou. It demonstrated also high resistance rate to antibiotics commonly used for infections treatment. Continuous monitoring and judicious antibiotic usage are required.

  3. Association of virulence plasmid and antibiotic resistance determinants with chromosomal multilocus genotypes in Mexican Salmonella enterica serovar Typhimurium strains

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    Silva Claudia

    2009-07-01

    Full Text Available Abstract Background Bacterial genomes are mosaic structures composed of genes present in every strain of the same species (core genome, and genes present in some but not all strains of a species (accessory genome. The aim of this study was to compare the genetic diversity of core and accessory genes of a Salmonella enterica subspecies enterica serovar Typhimurium (Typhimurium population isolated from food-animal and human sources in four regions of Mexico. Multilocus sequence typing (MLST and macrorestriction fingerprints by pulsed-field gel electrophoresis (PFGE were used to address the core genetic variation, and genes involved in pathogenesis and antibiotic resistance were selected to evaluate the accessory genome. Results We found a low genetic diversity for both housekeeping and accessory genes. Sequence type 19 (ST19 was supported as the founder genotype of STs 213, 302 and 429. We found a temporal pattern in which the derived ST213 is replacing the founder ST19 in the four geographic regions analyzed and a geographic trend in the number of resistance determinants. The distribution of the accessory genes was not random among chromosomal genotypes. We detected strong associations among the different accessory genes and the multilocus chromosomal genotypes (STs. First, the Salmonella virulence plasmid (pSTV was found mostly in ST19 isolates. Second, the plasmid-borne betalactamase cmy-2 was found only in ST213 isolates. Third, the most abundant integron, IP-1 (dfrA12, orfF and aadA2, was found only in ST213 isolates. Fourth, the Salmonella genomic island (SGI1 was found mainly in a subgroup of ST19 isolates carrying pSTV. The mapping of accessory genes and multilocus genotypes on the dendrogram derived from macrorestiction fingerprints allowed the establishment of genetic subgroups within the population. Conclusion Despite the low levels of genetic diversity of core and accessory genes, the non-random distribution of the accessory genes

  4. Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains in Italy and heterogeneity of inducibly resistant strains.

    Science.gov (United States)

    Giovanetti, E; Montanari, M P; Mingoia, M; Varaldo, P E

    1999-08-01

    A total of 387 clinical strains of erythromycin-resistant (MIC, >/=1 microg/ml) Streptococcus pyogenes, all isolated in Italian laboratories from 1995 to 1998, were examined. By the erythromycin-clindamycin double-disk test, 203 (52.5%) strains were assigned to the recently described M phenotype, 120 (31.0%) were assigned to the inducible macrolide, lincosamide, and streptogramin B resistance (iMLS) phenotype, and 64 (16.5%) were assigned to the constitutive MLS resistance (cMLS) phenotype. The inducible character of the resistance of the iMLS strains was confirmed by comparing the clindamycin MICs determined under normal testing conditions and those determined after induction by pregrowth in 0.05 microg of erythromycin per ml. The MICs of erythromycin, clarithromycin, azithromycin, josamycin, spiramycin, and the ketolide HMR3004 were then determined and compared. Homogeneous susceptibility patterns were observed for the isolates of the cMLS phenotype (for all but one of the strains, HMR3004 MICs were 0.5 to 8 microg/ml and the MICs of the other drugs were >128 microg/ml) and those of the M phenotype (resistance only to the 14- and 15-membered macrolides was recorded, with MICs of 2 to 32 microg/ml). Conversely, heterogeneous susceptibility patterns were observed in the isolates of the iMLS phenotype, which were subdivided into three distinct subtypes designated iMLS-A, iMLS-B, and iMLS-C. The iMLS-A strains (n = 84) were highly resistant to the 14-, 15-, and 16-membered macrolides and demonstrated reduced susceptibility to low-level resistance to HMR3004. The iMLS-B strains (n = 12) were highly resistant to the 14- and 15-membered macrolides, susceptible to the 16-membered macrolides (but highly resistant to josamycin after induction), and susceptible to HMR3004 (but intermediate or resistant after induction). The iMLS-C strains (n = 24) had lower levels of resistance to the 14- and 15-membered macrolides (with erythromycin MICs increasing two to four times after

  5. The non-clonality of drug resistance in Beijing-genotype isolates of Mycobacterium tuberculosis from the Western Cape of South Africa

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    Van Helden Paul D

    2010-11-01

    Full Text Available Abstract Background The Beijing genotype of M. tuberculosis is a virulent strain that is disseminating worldwide and has a strong association with drug resistance. In the Western Cape of South Africa, epidemiological studies have identified the R220 cluster of the Beijing genotype as a major contributor to a recent outbreak of drug-resistant tuberculosis. Although the outbreak is considered to be due to clonal transmission, the relationship among drug resistant isolates has not yet been established. Results To better understand the evolution of drug resistance among these strains, 14 drug-resistant clinical isolates of the Beijing genotype were sequenced by whole-genome sequencing, including eight from R220 and six from a more ancestral Beijing cluster, R86, for comparison. While each cluster shares a distinct resistance mutation for isoniazid, mapping of other drug-resistance mutations onto a phylogenetic tree constructed from single nucleotide polymorphisms shows that resistance mutations to many drugs have arisen multiple times independently within each cluster of isolates. Thus, drug resistance among these isolates appears to be acquired, not clonally derived. This observation suggests that, although the Beijing genotype as a whole might have selective advantages enabling its rapid dissemination, the XDR isolates are relatively less fit and do not propagate well. Although it has been hypothesized that the increased frequency of drug resistance in some Beijing lineages might be caused by a mutator phenotype, no significant shift in synonymous substitution patterns is observed in the genomes. Conclusion While MDR-TB is spreading by transmission in the Western Cape, our data suggests that further drug resistance (i.e. XDR-TB at this stage is acquired.

  6. Multicenter cross-sectional observational study of antibiotic resistance and the genotypes of Propionibacterium acnes isolated from Chinese patients with acne vulgaris.

    Science.gov (United States)

    Fan, Yukun; Hao, Fei; Wang, Weizhen; Lu, Yonghong; He, Li; Wang, Gang; Chen, Wenchieh

    2016-04-01

    Antibiotics are widely applied in management of acne vulgaris, which raises the issue of antibiotic resistance. Due to improper application and supervision of antibiotics, antibiotic resistance has become a serious problem in China. So, the efficacy of antimicrobial therapy in acne is unclear without an objective monitor of antibiotic resistance of Propionibacterium acnes. This cross-sectional, multicenter observational study is aimed at understanding the status of antibiotic resistance in P. acnes, investigating the measures of acne management in China and analyzing the genotypes of antibiotic-resistant strains of P. acnes. Altogether, 312 strains of P. acnes were collected from patients in five medical centers across central China after reviewing the corresponding medical history in detail. The samples underwent antibiotic susceptibility assays by agar dilution method with a total of 11 classes of antibiotics being tested. The antibiotic-resistant strains were screened and further analyzed by investigation of the genotypes regarding 23S rRNA, 16S rRNA and erm(X). The predominant resistance occurred in macrolides and lincomycin with an overall resistance rate of 47.8%. The resistance to tetracyclines was scarce with only two cases identified. The emergence of minimum inhibitory concentration elevation for tetracyclines is associated with its application history (P resistance strains were also spotted in Chinese subjects while other resistance determinants may also exist. The tetracyclines have been proved to be vastly susceptible while macrolides and lincomycin face a serious resistance status in China. © 2015 Japanese Dermatological Association.

  7. Genotypic characterization of quinolone resistant-Escherichia coli isolates from retail food in Morocco.

    Science.gov (United States)

    Nayme, Kaotar; Barguigua, Abouddihaj; Bouchrif, Brahim; Karraouan, Bouchra; El Otmani, Fatima; Elmdaghri, Naima; Zerouali, Khalid; Timinouni, Mohammed

    2017-02-01

    This study was conducted to assess the retail food as a possible vehicle for antimicrobial resistant, particularly quinolones resistant and pathogenic Escherichia coli. We determined the prevalence and characteristics of nalidixic acid (Nal) resistant E. coli isolates from diverse retail food samples. In all, 70 (28%) of 250 E. coli isolates studied were Nal-resistant E. coli and 91% of these were multi-drug resistant. Plasmid mediated quinolone resistance genes were identified in 32 isolates, including aac(6')-Ib-cr (n = 16), qnrS1 (n = 11) and qnrB19 (n = 7). Mutations in gyr A and par C genes were detected among 80% of the isolates, and the isolates showed substitution Ser83-Leu and Asp87-Asn in gyrA and Ser80-Ile in parC. In addition, three different gene cassettes were identified (aadA1, aadA7, aac(3)-Id) in 18%. Virulence-associated genes stx1, eae, sfa, hlyA and stx2 were found in six (8%), three (4%), two (3%), three (4%) and three (4%) isolates, respectively. E. coli isolates of phylogenetic group A were dominant (64%, 45/70). Pulsed field gel electrophoresis revealed none epidemiological relationship between these isolates. The results of this work report the higher frequency of Nal-resistant E. coli isolates from Moroccan retail food samples including MDR and pathogenic isolates.

  8. Detection by GenoType MTBDRsl test of complex mechanisms of resistance to second-line drugs and ethambutol in multidrug-resistant Mycobacterium tuberculosis complex isolates.

    Science.gov (United States)

    Brossier, Florence; Veziris, Nicolas; Aubry, Alexandra; Jarlier, Vincent; Sougakoff, Wladimir

    2010-05-01

    The GenoType MTBDRsl test rapidly detects resistance to ethambutol, fluoroquinolones, and second-line aminoglycosides (amikacin and kanamycin) and cyclic peptide (capreomycin) in Mycobacterium tuberculosis. A set of 41 multidrug-resistant (MDR) M. tuberculosis strains, 8 extensively drug-resistant (XDR) M. tuberculosis strains, and 3 non-MDR M. tuberculosis strains were tested by the MTBDRsl test and by DNA sequencing of the resistance-determining regions in gyrA and gyrB (fluoroquinolones [FQ]), rpsL (streptomycin), rrs and tlyA (aminoglycosides and/or cyclic peptide), and embB (ethambutol). The sensitivity and specificity of the MTBDRsl test were as follows: 87% and 96%, respectively, for fluoroquinolones; 100% for both for amikacin; 77% and 100%, respectively, for kanamycin, 80% and 98%, respectively, for capreomycin; and 57% and 92%, respectively, for ethambutol. Analysis of the discrepant results indicated that three FQ-resistant strains (including one XDR strain) with mutations in gyrB were missed by the MTBDRsl test and that one FQ-susceptible strain, identified as resistant by the MTBDRsl test, had a double mutation (T80A-A90G) in GyrA that did not confer resistance to FQ. Five strains (including two XDR strains) without mutations in rrs were monoresistant to aminoglycosides or cyclic peptide and were missed by the MTBDRsl test. Finally, 12/28 ethambutol-resistant strains had no mutation at codon 306 in embB, while 2/24 ethambutol-susceptible strains had such a mutation. In conclusion, the MTBDRsl test efficiently detects the most common mutations involved in resistance to fluoroquinolones, aminoglycosides/cyclic peptide, and ethambutol and accurately assesses susceptibility to amikacin. However, due to mutations not included in the test (particularly in gyrB) or resistance mechanisms not yet characterized (particularly those related to ethambutol resistance and to monoresistance to aminoglycosides or cyclic peptide), the wild-type results yielded by the

  9. Macrolide-lincosamide-resistant phenotypes and genotypes of Staphylococcus aureus isolated from bovine clinical mastitis.

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    Wang, Yang; Wu, Cong-Ming; Lu, Li-Ming; Ren, Gao-Wa Na; Cao, Xing-Yuan; Shen, Jian-Zhong

    2008-07-27

    The present study aimed to determine the prevalence and mechanisms of macrolide-lincosamide (ML) resistance in 72 Staphylococcus aureus isolates from cows with clinical mastitis. Minimum inhibitory concentrations (MIC) of ML antibiotics were determined by the broth microdilution technique, inducible ML resistance phenotype by the D test, and ML resistance genes by PCR assay. The isolates showed a high level of resistance to erythromycin (93.1%), azithromycin (93.1%), spiramycin (41.7%), tylosin (40.3%), tilmicosin (27.8%), and clindamycin (36.1%). Macrolide-lincosamide MIC(90) values were > or = 128 mg/L. Inducible ML resistance (iML) phenotype was detected in 52.8% (38/72) of isolates. In erythromycin-resistant (ER-R) strains, methylase genes ermB and ermC, efflux gene msrA/msrB, and inactivating enzyme genes lnuA and mphC were present alone or in various combinations, with ermB and ermC genes predominating. This is the first report of ML resistance genes ermB, mrsA/mrsB and mphC in S. aureus isolated from bovine mastitis. The occurrence of high levels of resistance to ML antibiotics among the S. aureus isolates, and the high rate of iML phenotype, indicate that appropriate alternative antibiotics should be prescribed for treating bovine mastitis caused by S. aureus. Furthermore, significant differences in the conformations of lactone rings of 16- and 14-membered macrolides could explain why some isolates with a constitutive ML resistance (cML) phenotype were sensitive to 16-membered macrolides alone. The different interaction of the 16-membered macrolides with the 50S ribosomal subunit is also presumably the reason why the susceptibility results of tilmcosin differed from those of tylosin and spiramycin.

  10. [Phenotypic and genotypic characterization of imipenem-resistant Pseudomonas aeruginosa isolated in a Buenos Aires hospital].

    Science.gov (United States)

    Cejas, D; Almuzara, M; Santella, G; Tuduri, A; Palombarani, S; Figueroa, S; Gutkind, G; Radice, M

    2008-01-01

    From 129 P. aeruginosa isolated at a health care centre located in Buenos Aires (Hospital "Eva Perón"), 14% produced IMP-13. Although 18 isolates were metallo-beta-lactamases (MBL) producers, only those isolates that displayed altered outer membrane protein profiles correlated with the resistant category according to CLSI or even Subcomisión de Antimicrobianos, SADEBAC, AAM. Phenotypic screening of metallo-beta-lactamases proved to be appropriate for detecting MBL producing isolates. IMP-13 producing isolates corresponded to at least five different clonal types, which not only suggests the dissemination of the resistant strain but also of the resistant marker.

  11. Phenotypic and genotypic analysis of multidrug-resistant tuberculosis in Ethiopia.

    NARCIS (Netherlands)

    Agonafir, M.; Lemma, E.; Wolde-Meskel, D.; Goshu, S.; Santhanam, A.; Girmachew, F.; Demissie, D.; Getahun, M.; Gebeyehu, M.; Soolingen, D. van

    2010-01-01

    SETTING: National Tuberculosis Reference Laboratory, Addis Ababa, Ethiopia. OBJECTIVES: To determine the drug susceptibility pattern of Mycobacterium tuberculosis isolates and to genetically characterise multidrug-resistant tuberculosis (MDR-TB) isolates. DESIGN: A total of 107 M. tuberculosis isola

  12. Detection and genotyping of vancomycin-resistant Enterococcus spp. by multiplex polymerase chain reaction in Korean aquatic environmental samples.

    Science.gov (United States)

    Nam, Sehee; Kim, Min-jeong; Park, Chulmin; Park, Jong-Geun; Maeng, Pil Jae; Lee, Gyu-Cheol

    2013-07-01

    The distribution characteristics of Enterococcus spp., which are indicators of fecal pollution, were investigated at 33 sites within the 3 major water systems of Korea. Enterococci were detected at concentrations ranging from 1 to 37 CFU/100mL in 41 of 132 samples (31.1%) from the 3 major water systems. The overall average detected concentration was 1.2 CFU/100mL, while the average concentration for all detection sites was 5.3 CFU/100mL. After optimized multiplex polymerase chain reaction (PCR) was performed with newly developed VanA, VanB, VanC-1, and VanC-2/3 primers, concentrations of vancomycin-resistant Enterococcus spp. (VRE) ranging from 1 to 23 CFU/100mL were detected in 17 of 132 samples (12.9%). Of 216 individual enterococcal colonies, 64 (29.6%) displayed the VanC genotype. The results of a susceptibility test to vancomycin showed that the range of the minimal inhibitory concentration (MIC), an indicator of bacterial resistance, was 4 to 24μg/mL, with the average MIC at 9.2±4.5μg/mL. Of the bacterial isolates, 1 colony with the VanC-1 genotype was identified as E. gallinarum by 16S rDNA sequencing, whereas the other 63 colonies had the VanC-2/3 genotype and were identified as E. casseliflavus. Although these results imply that the major head bays of Korea are not contaminated with the highly vancomycin-resistant VanA- or VanB-type VREs, the misuse of antibiotics should be prohibited to minimize the presence of VREs and to maintain a safe water supply for protecting the health of the general population. Based on the study results, we also recommend the implementation of a continuous, broad-spectrum inspection program for Enterococcus spp. and VRE contamination in the major head bays. Furthermore, the multiplex PCR method described in this study can be used effectively for this purpose.

  13. Phenotypic and Genotypic Detection of Metallo-beta-lactamases among Imipenem-Resistant Gram Negative Isolates

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    Mohammad Mohammadzadeh

    2016-08-01

    Full Text Available Background:   Imipenem-resistant gram negative bacteria, resulting from metallo-beta-lactamase (MBLs-producing strains have been reported to be among the important causes of nosocomial infections and of serious therapeutic problem worldwide. Because of their broad range, potent carbapenemase activity and resistance to inhibitors, these enzymes can confer resistance to almost all beta-lactams. The prevalence of metallo-beta-lactamase among imipenem-resistant Acinetobacter spp., Pseudomonas spp. and Enerobacteriaceae isolates is determined.Methods:   In this descriptive study 864 clinical isolates of Acinetobacter spp., Pseudomonas spp. and Enterobacteriaceae, were initially tested for imipenem susceptibility. The metallo-beta-lactamase production was detected using combined disk diffusion, double disk synergy test, and Hodge test. Then all imipenem resistant isolates were tested by PCR for imp, vim and ndm genes. Results:   Among 864 isolates, 62 (7.17 % were imipenem-resistant. Positive phonetypic test for metallo-beta-lactamase was 40 (64.5%, of which 24 (17.1% and 16 (9.2% isolates were Acinetobacter spp. and Pseudomonas spp., respectively. By PCR method 30 (48.4% of imipenem resistant Acinetobacter, and Pseudomonas isolates were positive for MBL-producing genes. None of the Enterobacteriaceae isolates were positive for metallo-beta-lactamase activity. Conclusion:   The results of this study are indicative of the growing number of nosocomial infections associated with multidrug-resistant gram negative bacteria in this region leading to difficulties in antibiotic therapy. Thereby, using of phenotypic methods can be helpful for management of this problem.

  14. Resistance to clarithromycin and genotypes in Helicobacter pylori strains isolated in Sicily.

    Science.gov (United States)

    Fasciana, Teresa; Calà, Cinzia; Bonura, Celestino; Di Carlo, Enza; Matranga, Domenica; Scarpulla, Giuseppe; Manganaro, Michele; Camilleri, Salvatore; Giammanco, Anna

    2015-11-01

    The resistance of Helicobacter pylori strains to clarithromycin is increasing in several developed countries and their association with a genetic pattern circulation has been variously explained as related to different geographical areas. In this study we have reported: the prevalence of the resistance of H. pylori, isolated in Sicily, to clarithromycin; the principal point of mutation associated with this resistance; and the more frequent association between resistance to clarithromycin and cagA, the EPIYA motif, and the vacA and oipA genes. Resistance to clarithromycin was detected in 25% of cases, the main genetic mutation involved being A2143G. The cagA gene was present in 48% of cases and the distribution of the EPIYA motif was: ABC in 35 cases; ABCC in 8 cases; ABCCC in 2 cases; ABC-ABCC in 2 cases; and ABC-ABCC-ABCCC in 1 case. Regarding the vacA allele, an s1i1m1 combination was detected in 35% of cases, s1i1m2 in 12 %, s1i2m2 in 12%, s2i2m2 in 40%, and a double s1m1-m2 mosaic in 1% of cases. The status of the oipA gene was 'off' in 45% of cases and 'on' in 55%. Resistance to clarithromycin was found to be high in Sicily, but no correlation was found among resistance to clarithromycin, the vacA gene and oipA status; a higher correlation was observed between resistant strains and cagA-negative strains.

  15. Interactions among insect-resistant soybean genotypes extracts with populations of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae susceptible and resistant to its nucleopolyhedrovirus

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    Giorla C. Piubelli

    2009-12-01

    Full Text Available Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV is being used in Brazil as a biological insecticide. Host plant resistance of soybean to insects is been searched for and some authors have mentioned the interference of plant chemistry in virus efficiency. Interactions among soybean extracts of genotypes used as a source of resistance (PI 274454 and PI 227687 with different AgMNPV concentrations in populations of A. geatalis susceptible (S and resistant (R to the virus were studied at laboratory condition. Higher mortality was observed when larvae fed on diets with extracts of the soybean genotypes compared with those fed on a plain diet (control. The mean lethal concentration (LC50 was reduced about 10 ties in the S-population fed on diets containing PI 274454 extracts and different concentrations of AgMNPV, compared to control diet. Additive effect was predominantly observed when larvae fed on diets with extracts of soybean genotypes (PI 274454 and PI 227687 and AgMNPV for both larval populations. The pupal weight was negatively influenced by the extracts incorporated to the diets compared to control, for both larval populations, notably for R-population. The results suggest that, in general, leaf extracts of soybean resistant genotype did not cause any harmful effect on virus efficiency.O nucleopoliedrovirus de Anticarsia gemmatalis (AgMNPV tem sido utilizado como um inseticida biológico no Brasil. A resistência de plantas de soja a insetos tem sido pesquisada e alguns autores têm mencionado a interferência de substâncias químicas de plantas sobre a eficiência de vírus. As interações entre extratos de genótipos de soja utilizados como fontes de resistência (PI 274454 e PI 227687 com diferentes concentrações do AgMNPV em populações de A. gemmatalis suscetível (S e resistente (R ao vírus foram estudadas em condições de laboratório. Mortalidades elevadas foram observadas quando as larvas foram alimentadas com dietas

  16. DR_SEQAN: a PC/Windows-based software to evaluate drug resistance using human immunodeficiency virus type 1 genotypes

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    Menéndez-Arias Luis

    2006-03-01

    Full Text Available Abstract Background Genotypic assays based on DNA sequencing of part or the whole reverse transcriptase (RT- and protease (PR-coding regions of the human immunodeficiency virus type 1 (HIV-1 genome have become part of the routine clinical management of HIV-infected individuals. However, the results are difficult to interpret due to complex interactions between mutations found in viral genes. Results DR_SEQAN is a tool to analyze RT and PR sequences. The program output includes a list containing all of the amino acid changes found in the query sequence in comparison with the sequence of a wild-type HIV-1 strain. Translation of codons containing nucleotide mixtures can result in potential ambiguities or heterogeneities in the amino acid sequence. The program identifies all possible combinations of 2 or 3 amino acids that derive from translation of triplets containing nucleotide mixtures. In addition, when ambiguities affect codons relevant for drug resistance, DR_SEQAN allows the user to select the appropriate mutation to be considered by the program's drug resistance interpretation algorithm. Resistance is predicted using a rule-based algorithm, whose efficiency and accuracy has been tested with a large set of drug susceptibility data. Drug resistance predictions given by DR_SEQAN were consistent with phenotypic data and coherent with predictions provided by other publicly available algorithms. In addition, the program output provides two tables showing published drug susceptibility data and references for mutations and combinations of mutations found in the analyzed sequence. These data are retrieved from an integrated relational database, implemented in Microsoft Access, which includes two sets of non-redundant core tables (one for combinations of mutations in the PR and the other for combinations in the RT. Conclusion DR_SEQAN is an easy to use off-line application that provides expert advice on HIV genotypic resistance interpretation. It is

  17. Functional genomic analysis of constitutive and inducible defense responses to Fusarium verticillioides infection in maize genotypes with contrasting ear rot resistance.

    Science.gov (United States)

    Lanubile, Alessandra; Ferrarini, Alberto; Maschietto, Valentina; Delledonne, Massimo; Marocco, Adriano; Bellin, Diana

    2014-08-25

    Fusarium verticillioides causes ear rot in maize (Zea mays L.) and accumulation of mycotoxins, that affect human and animal health. Currently, chemical and agronomic measures to control Fusarium ear rot are not very effective and selection of more resistant genotypes is a desirable strategy to reduce contaminations. A deeper knowledge of molecular events and genetic basis underlying Fusarium ear rot is necessary to speed up progress in breeding for resistance. A next-generation RNA-sequencing approach was used for the first time to study transcriptional changes associated with F. verticillioides inoculation in resistant CO441 and susceptible CO354 maize genotypes at 72 hours post inoculation. More than 100 million sequence reads were generated for inoculated and uninoculated control plants and analyzed to measure gene expression levels. Comparison of expression levels between inoculated vs. uninoculated and resistant vs. susceptible transcriptomes revealed a total number of 6,951 differentially expressed genes. Differences in basal gene expression were observed in the uninoculated samples. CO441 genotype showed a higher level of expression of genes distributed over all functional classes, in particular those related to secondary metabolism category. After F. verticillioides inoculation, a similar response was observed in both genotypes, although the magnitude of induction was much greater in the resistant genotype. This response included higher activation of genes involved in pathogen perception, signaling and defense, including WRKY transcription factors and jasmonate/ethylene mediated defense responses. Interestingly, strong differences in expression between the two genotypes were observed in secondary metabolism category: pathways related to shikimate, lignin, flavonoid and terpenoid biosynthesis were strongly represented and induced in the CO441 genotype, indicating that selection to enhance these traits is an additional strategy for improving resistance

  18. Resistance phenotypes and genotypes of Salmonella enterica subsp. enterica isolates from feed, pigs, and carcasses in Brazil.

    Science.gov (United States)

    Lopes, Graciela Volz; Pissetti, Caroline; da Cruz Payão Pellegrini, Débora; da Silva, Luis Eduardo; Cardoso, Marisa

    2015-02-01

    Salmonella enterica subsp. enterica plays a role as a foodborne pathogen worldwide. The consumption of contaminated pork has been associated with human salmonellosis and the increase in antimicrobial resistance among Salmonella from pigs and pork products is a concern. A total of 225 Salmonella isolates from feed mills, the lairage environment, and the intestinal contents of pigs and carcasses were investigated for their antimicrobial susceptibility. A MIC for ciprofloxacin was screened by agar dilution, and antimicrobial resistance genes were investigated by PCR assays. Among the tested isolates, 171 (76%) showed resistance to at least one antimicrobial agent, and 91 (40.4%) were multiresistant. Resistance occurred most frequently to tetracycline (54.5%), sulfonamides (39.6%), and streptomycin (33.7%). Thirty-two (94.1%) nalidixic acid-resistant isolates exhibited decreased susceptibility to ciprofloxacin. The resistance genes found were blaTEM (ampicillin), tet(A) (tetracycline), tet(B) (tetracycline/minocycline), sul1, sul2, and sul3 (sulfonamides), catA1 (chloramphenicol), floR (florfenicol/chloramphenicol), strA and strB (streptomycin), aph(3')-Ia (kanamycin), aac(3)-IIa and aac(3)-IVa (apramycin/gentamicin), aadA variant (streptomycin/spectinomycin), and dfrA1 (trimethoprim). Salmonella isolates from pig feces and carcasses displayed a higher frequency of resistance to most antimicrobials tested than isolates from feed mills. Common resistance gene profiles were found in isolates from the lairage and the intestinal content of pigs and carcasses, demonstrating that resistance genes selected on farms may be found in pork.

  19. Outbreak of infections by hepatitis B virus genotype A and transmission of genetic drug resistance in patients coinfected with HIV-1 in Japan.

    Science.gov (United States)

    Fujisaki, Seiichiro; Yokomaku, Yoshiyuki; Shiino, Teiichiro; Koibuchi, Tomohiko; Hattori, Junko; Ibe, Shiro; Iwatani, Yasumasa; Iwamoto, Aikichi; Shirasaka, Takuma; Hamaguchi, Motohiro; Sugiura, Wataru

    2011-03-01

    The major routes of hepatitis B virus (HBV) infection in Japan has been mother-to-child transmission (MTCT) and blood transfusion. However, HBV cases transmitted through sexual contact are increasing, especially among HIV-1-seropositive patients. To understand the molecular epidemiology of HBV in HBV/HIV-1 coinfection, we analyzed HBV genotypes and HIV-1 subtypes in HBV/HIV-1-coinfected patients at Nagoya Medical Center from 2003 to 2007. Among 394 HIV-1-infected Japanese men having sex with men (MSM) who were newly diagnosed during the study period, 31 (7.9%) tested positive for the hepatitis B virus surface antigen. HBV sequence analyses were successful in 26 cases, with 21 (80.7%) and 5 (19.3%) cases determined as genotypes A and C, respectively. Our finding that HBV genotype A was dominant in HIV-1-seropositive patients alerts clinicians to an alternative outbreak of HBV genotype A in the HIV-1-infected MSM population and a shift in HBV genotype from C to A in Japan. The narrow genetic diversity in genotype A cases suggests that genotype A has been recently introduced into the MSM population and that sexual contacts among MSM were more active than speculated from HIV-1 tree analyses. In addition, we found a lamivudine resistance mutation in one naïve case, suggesting a risk of drug-resistant HBV transmission. As genotype A infection has a higher risk than infection with other genotypes for individuals to become HBV carriers, prevention programs are urgently needed for the target population.

  20. Pre-existing isoniazid resistance, but not the genotype of Mycobacterium tuberculosis drives rifampicin resistance codon preference in vitro.

    NARCIS (Netherlands)

    Bergval, I.; Kwok, B.; Schuitema, A.; Kremer, K.; Soolingen, D. van; Klatser, P.; Anthony, R.

    2012-01-01

    Both the probability of a mutation occurring and the ability of the mutant to persist will influence the distribution of mutants that arise in a population. We studied the interaction of these factors for the in vitro selection of rifampicin (RIF)-resistant mutants of Mycobacterium tuberculosis. We

  1. Prevalence of Genotypes That Determine Resistance of Staphylococci to Macrolides and Lincosamides in Serbia

    Directory of Open Access Journals (Sweden)

    Milena Mišić

    2017-08-01

    Full Text Available Macrolides, lincosamides, and streptogramins (MLS resistance genes are responsible for resistance to these antibiotics in Staphylococcus infections. The purpose of the study was to analyze the distribution of the MLS resistance genes in community- and hospital-acquired Staphylococcus isolates. The MLS resistance phenotypes [constitutive resistance to macrolide–lincosamide–streptogramin B (cMLSb, inducible resistance to macrolide–lincosamide–streptogramin B (iMLSb, resistance to macrolide/macrolide–streptogramin B (M/MSb, and resistance to lincosamide–streptogramin A/streptogramin B (LSa/b] were determined by double-disc diffusion method. The presence of the MLS resistance genes (ermA, ermB, ermC, msrA/B, lnuA, lnuB, and lsaA were determined by end-point polymerase chain reaction in 179 isolates of staphylococci collected during 1-year period at the Center for Microbiology of Public Health Institute in Vranje. The most frequent MLS phenotype among staphylococcal isolates, both community-acquired and hospital-acquired, was iMLSb (33.4%. The second most frequent was M/MSb (17.6% with statistically significantly higher number of hospital-acquired staphylococcal isolates (p < 0.05. MLS resistance was mostly determined by the presence of msrA/B (35.0% and ermC (20.8% genes. Examined phenotypes were mostly determined by the presence of one gene, especially by msrA/B (26.3% and ermC (14.5%, but 15.6% was determined by a combination of two or more genes. M/MSb phenotype was the most frequently encoded by msrA/B (95.6% gene, LSa/b phenotype by lnuA (56.3% gene, and iMLSb phenotype by ermC (29.4% and ermA (25.5% genes. Although cMLSb phenotype was mostly determined by the presence of ermC (28.9%, combinations of two or more genes have been present too. This pattern was particularly recorded in methicillin-resistant Staphylococcus aureus (MRSA (58.3% and methicillin-resistant coagulase-negative staphylococci (MRCNS (90.9% isolates with c

  2. Genotypic drug resistance and long-term mortality in patients with triple-class antiretroviral drug failure

    DEFF Research Database (Denmark)

    Lohse, Nicolai; Jørgensen, Louise B; Kronborg, Gitte

    2007-01-01

    OBJECTIVE: To examine the prevalence of drug-resistance-associated mutations in HIV patients with triple-drug class virological failure (TCF) and their association with long-term mortality. DESIGN: Population-based study from the Danish HIV Cohort Study (DHCS). METHODS: We included all patients...... with increased mortality (mortality rate ratio [MRR] 2.3 [95% confidence interval (CI) 1.1-4.8]), as were the individual mutations T215Y (MRR 3.4 [95% CI 1.6-7.0]), G190A/S (MRR 3.2 [95% CI 1.6-6.6]) and V82F/A/T/S (MRR 2.5 [95% CI 1.2-5.3]). CONCLUSIONS: In HIV patients with TCF, the total number of genotypic...... resistance mutations and specific single mutations predicted mortality.OBJECTIVE: To examine the prevalence of drug-resistance-associated mutations in HIV patients with triple-drug class virological failure (TCF) and their association with long-term mortality. DESIGN: Population-based study from the Danish...

  3. SNP Discovery and QTL Mapping of Sclerotinia Basal Stalk Rot Resistance in Sunflower using Genotyping-by-Sequencing.

    Science.gov (United States)

    Talukder, Zahirul I; Seiler, Gerald J; Song, Qijian; Ma, Guojia; Qi, Lili

    2016-11-01

    Basal stalk rot (BSR), caused by the ascomycete fungus (Lib.) de Bary, is a serious disease of sunflower ( L.) in the cool and humid production areas of the world. Quantitative trait loci (QTL) for BSR resistance were identified in a sunflower recombinant inbred line (RIL) population derived from the cross HA 441 × RHA 439. A genotyping-by-sequencing (GBS) approach was adapted to discover single nucleotide polymorphism (SNP) markers. A genetic linkage map was developed comprised of 1053 SNP markers on 17 linkage groups (LGs) spanning 1401.36 cM. The RILs were tested in five environments (locations and years) for resistance to BSR. Quantitative trait loci were identified in each environment separately and also with integrated data across environments. A total of six QTL were identified in all five environments: one of each on LGs 4, 9, 10, 11, 16, and 17. The most significant QTL, and , were identified at multiple environments on LGs 10 and 17, explaining 31.6 and 20.2% of the observed phenotypic variance, respectively. The remaining four QTL, , , , and , were detected in only one environment on LGs 4, 9, 11, and 16, respectively. Each of these QTL explains between 6.4 and 10.5% of the observed phenotypic variation in the RIL population. Alleles conferring increased resistance were contributed by both parents. The potential of the and in marker-assisted selection (MAS) breeding are discussed. Copyright © 2016 Crop Science Society of America.

  4. SNP Discovery and QTL Mapping of Sclerotinia Basal Stalk Rot Resistance in Sunflower using Genotyping-by-Sequencing

    Directory of Open Access Journals (Sweden)

    Zahirul I. Talukder

    2016-11-01

    Full Text Available Basal stalk rot (BSR, caused by the ascomycete fungus (Lib. de Bary, is a serious disease of sunflower ( L. in the cool and humid production areas of the world. Quantitative trait loci (QTL for BSR resistance were identified in a sunflower recombinant inbred line (RIL population derived from the cross HA 441 × RHA 439. A genotyping-by-sequencing (GBS approach was adapted to discover single nucleotide polymorphism (SNP markers. A genetic linkage map was developed comprised of 1053 SNP markers on 17 linkage groups (LGs spanning 1401.36 cM. The RILs were tested in five environments (locations and years for resistance to BSR. Quantitative trait loci were identified in each environment separately and also with integrated data across environments. A total of six QTL were identified in all five environments: one of each on LGs 4, 9, 10, 11, 16, and 17. The most significant QTL, and , were identified at multiple environments on LGs 10 and 17, explaining 31.6 and 20.2% of the observed phenotypic variance, respectively. The remaining four QTL, , , , and , were detected in only one environment on LGs 4, 9, 11, and 16, respectively. Each of these QTL explains between 6.4 and 10.5% of the observed phenotypic variation in the RIL population. Alleles conferring increased resistance were contributed by both parents. The potential of the and in marker-assisted selection (MAS breeding are discussed.

  5. Phenotypic and genotypic characterization of methicillin-resistant Staphylococcus aureus from bovine mastitis

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    S. Hamid

    2017-03-01

    Full Text Available Aim: This study was conducted to determine the occurrence of methicillin-sensitive and Staphylococcus aureus (MSSA methicillin-resistant S. aureus (MRSA from bovine mastitis and to characterize them with respect to antibiotic resistance gene mecA. Materials and Methods: A total of 160 mastitic milk samples were screened for the presence of S. aureus. The presumptive positive isolates were confirmed using nuc and 23S rRNA gene-based polymerase chain reaction. All the confirmed isolates were subjected to in vitro antibiogram using a number of antibiotics. Isolates which showed resistance against methicillin were characterized for the presence of mecA gene. Results: Out of the total 160 milk samples, 36 (22.5% samples yielded S. aureus. The in vitro antibiogram revealed that 16.6% S. aureus isolates were resistant to all antibiotics screened for and 5.5% isolates were sensitive to all of them. Furthermore, the study found 94.4%, 83.3%, 77.7%, 66.6%, 50%, and 27.7% of S. aureus isolates resistant to penicillin, ampicillin, amoxicillin-sulbactam, enrofloxacin, ceftriaxone, and methicillin, respectively. Out of the 36 S. aureus isolates, only 6 (16.6% isolates were confirmed as MRSA while rest were MSSA. Conclusion: The higher occurrence of S. aureus-mediated mastitis was concluded due to improper hygienic and poor farm management. The multiple drug resistance reveals the indiscriminate use of drugs and presence of methicillin resistance gene determinant is an alarming situation as such infections are difficult to treat.

  6. Evaluation of rep-PCR/DiversiLab versus PFGE and spa typing in genotyping methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Aguadero, V; González Velasco, C; Vindel, A; Gonzalez Velasco, M; Moreno, J J

    2015-01-01

    Pulsed-field gel electrophoresis (PFGE) is the 'gold standard' for genotyping of methicillin-resistant Staphylococcus aureus (MRSA); however, the DiversiLab (DL) system, based on rep-PCR, is faster, simpler and could be better adapted to daily routine hospital work. We genotyped 100 MRSA isolates using PFGE, DL, and spa typing, and evaluated the discriminatory power of each technique and the correlation between them by Simpson's index(SI) and adjusted Rand coefficient (ARI), respectively. The isolates were from clinical samples from eight hospitals in Extremadura (Spain) during 2010. DL separated the 100 MRSA into 18 patterns, with 69% of the isolates grouped into four predominant patterns. spa typing reported 17 spa types, classifying 69% of MRSA into two major types (t067 and t002). PFGE revealed the existence of 27 patterns, gathering 54% of MRSA into three pulse types (E8a, E7a and E7b). SI values were 0.819, 0.726, 0.887 and 0.460 for DL, spa typing, PFGE and CC-BURP, respectively. ARI values of DL over PFGE, spa typing and CC-BURP were 0.151, 0.321 and 0.071, respectively. DL has less discriminatory power than PFGE but more than spa typing. The concordance of DL with PFGE is low, primarily because DL does not discriminate between the three predominant MRSA pulse types in our environment.

  7. Anti-folate drug resistance in Africa: meta-analysis of reported dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) mutant genotype frequencies in African Plasmodium falciparum parasite populations.

    Science.gov (United States)

    Sridaran, Sankar; McClintock, Shannon K; Syphard, Luke M; Herman, Karen M; Barnwell, John W; Udhayakumar, Venkatachalam

    2010-08-30

    Mutations in the dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) genes of Plasmodium falciparum are associated with resistance to anti-folate drugs, most notably sulphadoxine-pyrimethamine (SP). Molecular studies document the prevalence of these mutations in parasite populations across the African continent. However, there is no systematic review examining the collective epidemiological significance of these studies. This meta-analysis attempts to: 1) summarize genotype frequency data that are critical for molecular surveillance of anti-folate resistance and 2) identify the specific challenges facing the development of future molecular databases. This review consists of 220 studies published prior to 2009 that report the frequency of select dhfr and dhps mutations in 31 African countries. Maps were created to summarize the location and prevalence of the highly resistant dhfr triple mutant (N51I, C59R, S108N) genotype and dhps double mutant (A437G and K540E) genotype in Africa. A hierarchical mixed effects logistic regression was used to examine the influence of various factors on reported mutant genotype frequency. These factors include: year and location of study, age and clinical status of sampled population, and reporting conventions for mixed genotype data. A database consisting of dhfr and dhps mutant genotype frequencies from all African studies that met selection criteria was created for this analysis. The map illustrates particularly high prevalence of both the dhfr triple and dhps double mutant genotypes along the Kenya-Tanzania border and Malawi. The regression model shows a statistically significant increase in the prevalence of both the dhfr triple and dhps double mutant genotypes in Africa. Increasing prevalence of the dhfr triple mutant and dhps double mutant genotypes in Africa are consistent with the loss of efficacy of SP for treatment of clinical malaria in most parts of this continent. Continued assessment of the effectiveness

  8. Anti-folate drug resistance in Africa: meta-analysis of reported dihydrofolate reductase (dhfr and dihydropteroate synthase (dhps mutant genotype frequencies in African Plasmodium falciparum parasite populations

    Directory of Open Access Journals (Sweden)

    Sridaran Sankar

    2010-08-01

    Full Text Available Abstract Background Mutations in the dihydrofolate reductase (dhfr and dihydropteroate synthase (dhps genes of Plasmodium falciparum are associated with resistance to anti-folate drugs, most notably sulphadoxine-pyrimethamine (SP. Molecular studies document the prevalence of these mutations in parasite populations across the African continent. However, there is no systematic review examining the collective epidemiological significance of these studies. This meta-analysis attempts to: 1 summarize genotype frequency data that are critical for molecular surveillance of anti-folate resistance and 2 identify the specific challenges facing the development of future molecular databases. Methods This review consists of 220 studies published prior to 2009 that report the frequency of select dhfr and dhps mutations in 31 African countries. Maps were created to summarize the location and prevalence of the highly resistant dhfr triple mutant (N51I, C59R, S108N genotype and dhps double mutant (A437G and K540E genotype in Africa. A hierarchical mixed effects logistic regression was used to examine the influence of various factors on reported mutant genotype frequency. These factors include: year and location of study, age and clinical status of sampled population, and reporting conventions for mixed genotype data. Results A database consisting of dhfr and dhps mutant genotype frequencies from all African studies that met selection criteria was created for this analysis. The map illustrates particularly high prevalence of both the dhfr triple and dhps double mutant genotypes along the Kenya-Tanzania border and Malawi. The regression model shows a statistically significant increase in the prevalence of both the dhfr triple and dhps double mutant genotypes in Africa. Conclusion Increasing prevalence of the dhfr triple mutant and dhps double mutant genotypes in Africa are consistent with the loss of efficacy of SP for treatment of clinical malaria in most parts

  9. Genotypic and phenotypic characteristics of aminoglycoside-resistant Mycobacterium tuberculosis isolates in Latvia.

    Science.gov (United States)

    Bauskenieks, Matiss; Pole, Ilva; Skenders, Girts; Jansone, Inta; Broka, Lonija; Nodieva, Anda; Ozere, Iveta; Kalvisa, Adrija; Ranka, Renate; Baumanis, Viesturs

    2015-03-01

    Mutations causing resistance to aminoglycosides, such as kanamycin (KAN), amikacin (AMK), and streptomycin, are not completely understood. In this study, polymorphisms of aminoglycoside resistance influencing genes such as rrs, eis, rpsL, and gidB in 41 drug-resistant and 17 pan-sensitive Mycobacterium tuberculosis clinical isolates in Latvia were analyzed. Mutation A1400G in rrs gene was detected in 92% isolates with high resistance level to KAN and diverse MIC level to AMK. Mutations in promoter region of eis were detected in 80% isolates with low-level MIC of KAN. The association of K43R mutation in rpsL gene, a mutation in the rrs gene at position 513, and various polymorphisms in gidB gene with distinct genetic lineages of M. tuberculosis was observed. The results of this study suggest that association of different controversial mutations of M. tuberculosis genes to the drug resistance phenotype should be done in respect to genetic lineages.

  10. Genotypic drug resistance and long-term mortality in patients with triple-class antiretroviral drug failure

    DEFF Research Database (Denmark)

    Lohse, Nicolai; Jørgensen, Louise B; Kronborg, Gitte

    2007-01-01

    OBJECTIVE: To examine the prevalence of drug-resistance-associated mutations in HIV patients with triple-drug class virological failure (TCF) and their association with long-term mortality. DESIGN: Population-based study from the Danish HIV Cohort Study (DHCS). METHODS: We included all patients...... with increased mortality (mortality rate ratio [MRR] 2.3 [95% confidence interval (CI) 1.1-4.8]), as were the individual mutations T215Y (MRR 3.4 [95% CI 1.6-7.0]), G190A/S (MRR 3.2 [95% CI 1.6-6.6]) and V82F/A/T/S (MRR 2.5 [95% CI 1.2-5.3]). CONCLUSIONS: In HIV patients with TCF, the total number of genotypic...

  11. Predominance and high antibiotic resistance of the emerging Clostridium difficile genotypes NAPCR1 and NAP9 in a Costa Rican hospital over a 2-year period without outbreaks.

    Science.gov (United States)

    López-Ureña, Diana; Quesada-Gómez, Carlos; Montoya-Ramírez, Mónica; del Mar Gamboa-Coronado, María; Somogyi, Teresita; Rodríguez, César; Rodríguez-Cavallini, Evelyn

    2016-05-11

    Clostridium difficile is the major causative agent of nosocomial antibiotic-associated diarrhea. In a 2009 outbreak of C. difficile-associated diarrhea that was recorded in a major Costa Rican hospital, the hypervirulent NAP1 strain (45%) predominated together with a local genotype variant (NAPCR1, 31%). Both strains were fluoroquinolone-resistant and the NAPCR1 genotype, in addition, was resistant to clindamycin and rifampicin. We now report on the genotypes and antibiotic susceptibilities of 68 C. difficile isolates from a major Costa Rican hospital over a 2-year period without outbreaks. In contrast to our previous findings, no NAP1 strains were detected, and for the first time in a Costa Rican hospital, a significant fraction of the isolates were NAP9 strains (n=14, 21%). The local NAPCR1 genotype remained prevalent (n=18, 26%) and coexisted with 14 strains (21%) of classic hospital NAP types (NAP2, NAP4, and NAP6), eight new genotypes (12%), four environmental strains classified as NAP10 or NAP11 (6%), three strains without NAP designation (4%) and seven non-toxigenic strains (10%). All 68 strains were resistant to ciprofloxacin, 88% were resistant to clindamycin and 50% were resistant to moxifloxacin and rifampicin. Metronidazole and vancomycin susceptibilities were universal. The NAPCR1 and NAP9 strains, which have been associated with more severe clinical infections, were more resistant to antibiotics than the other strains. Altogether, our results confirm that the epidemiology of C. difficile infection is dynamic and that A(-)B(+) strains from the NAP9 type are on the rise not only in the developed world. Moreover, our results reveal that the local NAPCR1 strains still circulate in the country without causing outbreaks but with equally high antibiotic-resistance rates and levels.

  12. Prevalence and genotypic relatedness of methicillin resistant Staphylococcus aureus in a tertiary care hospital

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    B A Fomda

    2014-01-01

    Full Text Available Background: Methicillin-resistant Staphylococcus aureus (MRSA is the most common multidrug-resistant pathogen causing nosocomial infections across the world. MRSA is not only associated with significant mortality and morbidity but also places a large economic strain on our health care system. MRSA isolates are also typically resistant to multiple, non-β-lactam antibiotics. We conducted a prospective study in a tertiary care hospital, to determine the prevalence of MRSA and to establish the clonal distribution of MRSA isolates recovered from various clinical specimens. Materials and Methods: Clinical samples were cultured and S. aureus was identified as per standard microbiological procedures. Susceptibility testing was done by agar disk diffusion and minimum inhibitory concentration (MIC method as recommended by CLSI. Methicillin resistance was detected by phenotypic methods namely, oxacillin disc diffusion (ODD, minimum inhibitory concentration (MIC of oxacillin, cefoxitin disk diffusion (CDD, and MIC of cefoxitin. Amplification of mecA gene by PCR was used as gold standard for detection of methicillin resistance. Pulsed field gel electrophoresis (PFGE typing was performed for MRSA isolates. Results: Out of 390 S. aureus isolates, 154 (39.48% isolates were MRSA and 236 (60.51% isolates were MSSA. Penicillin was the least effective antibacterial drug against the hospital associated S. aureus isolates with 85.64% resistance rate. All the isolates were susceptible to vancomycin. The MRSA showed a high level of resistance to all antimicrobials in general in comparison to the MSSA and the difference was statistically significant (P < 0.05. Multiplex PCR performed for all strains showed amplification of both the mecA and nucA genes in MRSA strains whereas MSSA strains showed amplification of only nucA gene. PFGE of these isolates showed 10 different patterns. Conclusion: Prevalence of MRSA in our hospital was 39.48%. Most of these isolates were

  13. Acinetobacter baumannii Isolated from Lebanese Patients: Phenotypes and Genotypes of Resistance, Clonality, and Determinants of Pathogenicity

    Science.gov (United States)

    Dahdouh, Elias; Hajjar, Micheline; Suarez, Monica; Daoud, Ziad

    2016-01-01

    Introduction: Acinetobacter baumannii is a nosocomial pathogen that usually affects critically ill patients. High mortality rates have been associated with MDR A. baumannii infections. Carbapenem resistance among these isolates is increasing worldwide and is associated with certain International Clones (ICs) and oxacillinases (OXAs). Moreover, this organism possesses a wide range of virulence factors, whose expression is not yet fully understood. In this study, clinical A. baumannii isolates are characterized in terms of antibiotic resistance, mechanisms of carbapenem resistance, clonality, and virulence. Materials and Methods: A. baumannii clinical isolates (n = 90) where obtained from a tertiary care center in Beirut, Lebanon. API 20NE strips in addition to the amplification of blaOXA−51−like were used for identification. Antibiotic susceptibility testing by disk diffusion was then performed in addition to PCRs for the detection of the most commonly disseminated carbapenemases. Clonality was determined by tri-locus PCR typing and doubling times were determined for isolates with varying susceptibility profiles. Biofilm formation, hemolysis, siderophore production, proteolytic activity, and surface motility was then determined for all the isolates. Statistical analysis was then performed for the determination of associations. Results and Discussion: 81 (90%) of the isolates were resistant to carbapenems. These high rates are similar to other multi-center studies in the country suggesting the need of intervention on a national level. 74 (91.3%) of the carbapenem resistant isolates harbored blaOXA−23−like including two that also harbored blaOXA−24−like. 88.9% of the A. baumannii isolates pertained to ICII and three other international clones were detected, showing the wide dissemination of clones into geographically distinct locations. Virulence profiles were highly diverse and no specific pattern was observed. Nevertheless, an association between

  14. NS3 Resistance-Associated Variants (RAVs) in Patients Infected with HCV Genotype 1a in Spain

    Science.gov (United States)

    Jimenez-Sousa, María Ángeles; Gutiérrez-Rivas, Mónica; Álvaro-Meca, Alejandro; García-Álvarez, Mónica; Harrigan, P. Richard; Fedele, Cesare Giovanni; Briz, Verónica

    2016-01-01

    Background Resistance-associated variants have been related to treatment failure of hepatitis C virus (HCV) therapy with direct-acting antiviral drugs. The aim of our study was to analyze the prevalence of clinically relevant resistance-associated variants within NS3 in patients infected with HCV genotype 1a (GT1a) in Spain. Methods We performed a cross-sectional study on 2568 patients from 115 hospitals throughout Spain (2014–2015). The viral NS3 protease gene was amplified by nested polymerase chain reaction and sequenced by Sanger sequencing using an ABI PRISM 377 DNA sequencer. Additionally, clade information for genotype 1a was obtained by using the software geno2pheno (http://hcv.geno2pheno.org/). Results In total, 875 out of 2568 samples were from human immunodeficiency virus (HIV)/HCV-coinfected patients. Q80K was the main RAV found in our patients (11.1%) and the rest of the resistance-associated variants had a lower frequency, including S122G (6.23%), T54S (3.47%), V55A (2.61%), and V55I (2.15%), which were among the most frequent after Q80K. Overall, 286 samples had the Q80K polymorphism (11.1%) and 614 (23.9%) were GT1a clade I. HIV/HCV-coinfected patients had a higher frequency of Q80K and GT1a clade I than HCV-monoinfected patients (12.9% vs. 9.6% [p = 0.012] and 28.5% vs. 21.4% [p<0.001], respectively). Both the prevalence of Q80K and GT1a clade I were not uniform throughout the country (p<0.001), which ranged from 7.3%-22.2% and 15.7%-42.5%, respectively. The frequency of the Q80K polymorphism was far higher in patients infected with GT1a clade I than in patients infected with GT1a clade II (41.5% vs. 1.6%; p<0.001). Conclusions The prevalence of most resistance-associated variants in NS3 was low in patients infected with HCV GT1a in Spain, except for Q80K (11.1%), which was also notably higher in HIV/HCV-coinfected patients. The vast majority of Q80K polymorphisms were detected in GT1a clade I. PMID:27685471

  15. Fluconazole and Echinocandin Resistance of Candida glabrata Correlates Better with Antifungal Drug Exposure Rather than with MSH2 Mutator Genotype in a French Cohort of Patients Harboring Low Rates of Resistance

    Science.gov (United States)

    Dellière, Sarah; Healey, Kelley; Gits-Muselli, Maud; Carrara, Bastien; Barbaro, Alessandro; Guigue, Nicolas; Lecefel, Christophe; Touratier, Sophie; Desnos-Ollivier, Marie; Perlin, David S.; Bretagne, Stéphane; Alanio, Alexandre

    2016-01-01

    Candida glabrata is a major pathogenic yeast in humans that is known to rapidly acquire resistance to triazole and echinocandin antifungal drugs. A mutator genotype (MSH2 polymorphism) inducing a mismatch repair defect has been recently proposed to be responsible for resistance acquisition in C. glabrata clinical isolates. Our objectives were to evaluate the prevalence of antifungal resistance in a large cohort of patients in Saint-Louis hospital, Paris, France, some of whom were pre-exposed to antifungal drugs, as well as to determine whether MSH2 polymorphisms are associated with an increased rate of fluconazole or echinocandin resistance. We collected 268 isolates from 147 patients along with clinical data and previous antifungal exposure. Fluconazole and micafungin minimal inhibition concentrations (MICs) were tested, short tandem repeat genotyping was performed, and the MSH2 gene was sequenced. According to the European Committee on Antimicrobial Susceptibility breakpoints, 15.7% of isolates were resistant to fluconazole (MIC > 32 mg/L) and 0.7% were resistant to micafungin (MIC > 0.03 mg/L). A non-synonymous mutation within MSH2 occurred in 44% of the isolates, and 17% were fluconazole resistant. In comparison, fluconazole resistant isolates with no MSH2 mutation represented 15% (P = 0.65). MSH2 polymorphisms were associated with the short tandem repeat genotype. The rate of echinocandin resistance is low and correlates with prior exposure to echinocandin. The mutator genotype was not associated with enrichment in fluconazole resistance but instead corresponded to rare and specific genotypes. PMID:28066361

  16. Select small core structure carbamates exhibit high contact toxicity to "carbamate-resistant" strain malaria mosquitoes, Anopheles gambiae (Akron.

    Directory of Open Access Journals (Sweden)

    Dawn M Wong

    Full Text Available Acetylcholinesterase (AChE is a proven target for control of the malaria mosquito (Anopheles gambiae. Unfortunately, a single amino acid mutation (G119S in An. gambiae AChE-1 (AgAChE confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (k(cat of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold. The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC(50>5,000 μg/mL. However, one oxime methylcarbamate (aldicarb and five pyrazol-4-yl methylcarbamates (4a-e showed good to excellent toxicity to the Akron strain (LC(50 = 32-650 μg/mL. These results suggest that appropriately functionalized "small-core" carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito.

  17. Select small core structure carbamates exhibit high contact toxicity to "carbamate-resistant" strain malaria mosquitoes, Anopheles gambiae (Akron).

    Science.gov (United States)

    Wong, Dawn M; Li, Jianyong; Chen, Qiao-Hong; Han, Qian; Mutunga, James M; Wysinski, Ania; Anderson, Troy D; Ding, Haizhen; Carpenetti, Tiffany L; Verma, Astha; Islam, Rafique; Paulson, Sally L; Lam, Polo C-H; Totrov, Maxim; Bloomquist, Jeffrey R; Carlier, Paul R

    2012-01-01

    Acetylcholinesterase (AChE) is a proven target for control of the malaria mosquito (Anopheles gambiae). Unfortunately, a single amino acid mutation (G119S) in An. gambiae AChE-1 (AgAChE) confers resistance to the AChE inhibitors currently approved by the World Health Organization for indoor residual spraying. In this report, we describe several carbamate inhibitors that potently inhibit G119S AgAChE and that are contact-toxic to carbamate-resistant An. gambiae. PCR-RFLP analysis was used to confirm that carbamate-susceptible G3 and carbamate-resistant Akron strains of An. gambiae carry wild-type (WT) and G119S AChE, respectively. G119S AgAChE was expressed and purified for the first time, and was shown to have only 3% of the turnover number (k(cat)) of the WT enzyme. Twelve carbamates were then assayed for inhibition of these enzymes. High resistance ratios (>2,500-fold) were observed for carbamates bearing a benzene ring core, consistent with the carbamate-resistant phenotype of the G119S enzyme. Interestingly, resistance ratios for two oxime methylcarbamates, and for five pyrazol-4-yl methylcarbamates were found to be much lower (4- to 65-fold). The toxicities of these carbamates to live G3 and Akron strain An. gambiae were determined. As expected from the enzyme resistance ratios, carbamates bearing a benzene ring core showed low toxicity to Akron strain An. gambiae (LC(50)>5,000 μg/mL). However, one oxime methylcarbamate (aldicarb) and five pyrazol-4-yl methylcarbamates (4a-e) showed good to excellent toxicity to the Akron strain (LC(50) = 32-650 μg/mL). These results suggest that appropriately functionalized "small-core" carbamates could function as a resistance-breaking anticholinesterase insecticides against the malaria mosquito.

  18. Quantitative Analysis of the Early Powdery Mildew Infection Stages on Resistant Barley Genotypes

    DEFF Research Database (Denmark)

    Andersen, J. B.; Torp, J.

    1986-01-01

    A classification system was developed, that allowed quantification of the leaf surface development of the barley powdery mildew fungus on barley. An experiment with Manchuria and Pallas as susceptible controls and 4 resistance gene each represented by three lines with different gene backgrounds s...

  19. Genotyping and antimicrobial resistance genes of Yersinia ruckeri isolates from rainbow trout farms.

    Science.gov (United States)

    Duman, Muhammed; Altun, Soner; Cengiz, Murat; Saticioglu, Izzet Burcin; Buyukekiz, Ayse Gul; Sahinturk, Pinar

    2017-06-19

    In this study, we compared 142 Yersinia ruckeri isolates collected between 2013 and 2016 from 6 different regions in Turkey. A total of 18 different genogroups were found, though most of the isolates clustered into the same genogroup as serotype O1. As immunization of fish with inactivated Y. ruckeri by injection, immersion, or feeding provide minimal protection against Y. ruckeri infection in Turkey, many fish producers use antimicrobials unrestrictedly, resulting in antimicrobial resistance in aquatic pathogens. Accordingly, we investigated resistance to the antimicrobials most commonly used to treat yersiniosis. More than 80% of the Y. ruckeri isolates were susceptible to sulfamethoxazole-trimethoprim (SXT), florfenicol (FFC), and tetracycline, whereas none were susceptible to sulfamethoxazole. The most commonly used antimicrobials (SXT and FFC) can be effectively administered because the resistance levels to these drugs are the lowest among those reported for agents used to control enteric red mouth disease (12.6 and 14.7%, respectively). In conclusion, to the best of our knowledge, this study is the first characterization of the antimicrobial resistance genes floR, sulI, tetC, tetD, and tetE in Y. ruckeri isolates from aquaculture. Additionally, we detected the sulII gene but not the tetA, tetB, tetM, tetS, or sulIII genes.

  20. Genotypic characterization of multi-drug-resistant Mycobacterium tuberculosis isolates in Myanmar.

    Science.gov (United States)

    Aye, Khin Saw; Nakajima, Chie; Yamaguchi, Tomoyuki; Win, Min Min; Shwe, Mu Mu; Win, Aye Aye; Lwin, Thandar; Nyunt, Wint Wint; Ti, Ti; Suzuki, Yasuhiko

    2016-03-01

    The number of multi-drug-resistant tuberculosis (MDR-TB) cases is rising worldwide. As a countermeasure against this situation, the implementation of rapid molecular tests to identify MDR-TB would be effective. To develop such tests, information on the frequency and distribution of mutations associating with phenotypic drug resistance in Mycobacterium tuberculosis is required in each country. During 2010, the common mutations in the rpoB, katG and inhA of 178 phenotypically MDR M. tuberculosis isolates collected by the National Tuberculosis Control Program (NTP) in Myanmar were investigated by DNA sequencing. Mutations affecting the 81-bp rifampicin (RIF) resistance-determining region (RRDR) of the rpoB were identified in 127 of 178 isolates (71.3%). Two of the most frequently affected codons were 531 and 526, with percentages of 48.3% and 14.0% respectively. For isoniazid (INH) resistance, 114 of 178 MDR-TB isolates (64.0%) had mutations in the katG in which a mutation-conferring amino acid substitution at codon 315 from Ser to Thr was the most common. Mutations in the inhA regulatory region were also detected in 20 (11.2%) isolates, with the majority at position -15. Distinct mutation rate and pattern from surrounding countries might suggest that MDR-TB has developed and spread domestically in Myanmar.

  1. Genotypic characterization, invasion index and antimicrobial resistance pattern in Listeria monocytogenes strains isolated from clinical samples

    Institute of Scientific and Technical Information of China (English)

    Behrooz Sadeghi Kalani; Abazar Pournajaf; Mansour Sedighi; Abbas Bahador; Gholamreza Irajian; Firuzeh Valian

    2015-01-01

    Objective: To evaluate antimicrobial resistance, invasion index and genetic profile in Listeriamonocytogenes isolated from clinical samples. Methods: At all, 170 clinical samples were collected from patients with spontaneous abortions hospitalized in Shariati hospital in Tehran during June 2010 to August 2013. Invasion index was determined using HeLa cells. The multiple-locus variable-number tandem-repeats analysis (MLVA) was used for evaluation of genetic relatedness. Results: Out of 14 L. monocytogenes isolates, 4 (28.57%), 2 (14.28%), 0 (0%), 5 (35.71%) and 3 (21.42%) were isolated from placental tissue, urine, blood, vaginal and rectal swabs, respectively. High resistance to penicillin and multidrug resistant were found amongst isolates. The invasion index was in the range of 0.001-0.007. Seven different types were obtained by MLVA assay and type 2 and 3 with 4 strains were the most frequent type. Strains isolated from the vagina and the placenta of the same type were also more resistant to penicillin. Conclusions: Since MLVA is a high-throughput screening method that is fairly inexpensive, easy to accomplish, rapid, and trustworthy, it is well suited to interlaboratory comparisons during epidemiological investigations. Also further studies of larger samples from a variety of sources such as food and animal specimens recommended comparing by MLVA method.

  2. Antimicrobial Resistance and Genotypic Diversity of Campylobacter Isolated from Pig, Dairy and Beef Cattle in Tanzania

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    Isaac eKashoma

    2015-11-01

    Full Text Available Foodborne Campylobacter infections pose a serious threat to public health worldwide. However, the occurrence and characteristics of Campylobacter in food animals and products remain largely unknown in Tanzania. The objective of this study was to determine the prevalence, antibiotic resistance, and genetic profiles (sequence types, STs of Campylobacter isolated from feces of pigs and dairy and beef cattle in Tanzania. Overall, 259 (~ 30% of 864 samples were positive for Campylobacter spp, which were detected in 32.5%, 35.4%, and 19.6% of the pig, dairy, and beef cattle samples, respectively. Multiplex PCR analysis identified 64.5% and 29.3% of the Campylobacter isolates as C. coli and C. jejuni, respectively. The majority (91.9% of the isolates from pig samples were identified as C. coli, while C. jejuni accounted for 65.5% of the isolates from cattle. Antimicrobial susceptibility testing using the disk diffusion assay and the broth microdilution method revealed resistance to: ampicillin (70% and 76%, gentamicin (1.8% and 12.6%, respectively, streptomycin (65.8% and 74.8%, erythromycin (41.4% and 48.7%, tetracycline (18.9% and 23.4%, and ciprofloxacin (14.4% and 7.2%. Resistance to nalidixic acid (39.6%, azithromycin (13.5%, and chloramphenicol (4.5% was determined using the disk diffusion assay only, while resistance to tylosin (38.7% was quantified using the broth microdilution method. Multilocus sequence typing of 111 Campylobacter isolates resulted in the identification of 48 STs (26 C. jejuni and 22 C. coli of which 7 were novel (6 C. jejuni and 1 C. coli. Taken together, this study revealed the high prevalence, genetic diversity and antimicrobial resistance of Campylobacter in important food animals in Tanzania, which highlights the urgent need for the surveillance and control of Campylobacter in this country.

  3. Resistência à ferrugem da folha e potencial produtivo em genótipos de trigo Leaf rust resistance and grain yield potential in wheat genotypes

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    João Carlos Felicio

    2008-12-01

    Full Text Available Foram avaliados 18 genótipos de trigo provenientes de cruzamentos entre a linhagem BH1146//AA"S"/WIN"S", oriunda de cruzamentos interespecíficos entre Triticum aestivum L. e Triticum durum L., e as cultivares IAC 289 e IAC 1004, em experimentos instalados em condições de sequeiro em Manduri (Zona A; Capão Bonito e Itapeva (Zona B e Paranapanema (Zona C, no período de 2003 a 2005. As avaliações dos genótipos ao agente causal da ferrugem da folha foram feitas no estádio de plântulas em casa de vegetação, onde os genótipos foram submetidos à inoculação, individualmente, com esporos de 12 raças de Puccinia triticina, as quais representavam o espectro de virulência do patógeno ocorrente no Brasil e sob infecção natural no campo. Foram avaliados os rendimentos de grãos de cada genótipo nas diferentes regiões e no conjunto dos experimentos, bem como a estabilidade e adaptabilidade. Os genótipos 8 (BH1146//AA"S"/WIN"S"/3/BUC/FKL//MYNA/VUL, 12 e 14 (BH1146//AA"S"/WIN"S"/3/VEE//DOVE/BUC destacaram-se por sua resistência às raças fisiológicas de Puccinia triticina em casa de vegetação na fase de plântulas. Em condições de infecção natural da doença, destacaram-se os genótipos 4, 5, 8, 12, 13, 16 e 20 e a cultivar IAC 1004 (T. durum com resistência à ferrugem da folha no triênio. Os melhores rendimentos de grãos foram obtidos pelos genótipos 8 (BH1146//AA"S"/WIN"S"/3/BUC/FKL//MYNA/VUL, 7 (BH1146//AA"S"/WIN"S"/3/HANN*2/PRL e 18 (CMH 75.A.66/ SERI/3/BH1146//AA"S"/WIN"S". O menor foi obtido pelo genótipo 16 (KAUZ/3/ BH1146//AA"S"/WIN"S".Eighteen wheat genotypes obtained from crosses between the parental line BH1146//AA"S"/WIN"S" originated from interespecific crosses between Triticum aestivum L. and Triticum durum L. and the cultivars IAC 289 and IAC 1004 were evaluated in experiments carried out in upland conditions at Manduri (Zone A; Capão Bonito and Itapeva (Zone B and Paranapanema (Zone C, in the State of S

  4. Feasibility of the GenoType MTBDRsl assay for fluoroquinolone, amikacin-capreomycin, and ethambutol resistance testing of Mycobacterium tuberculosis strains and clinical specimens.

    Science.gov (United States)

    Hillemann, Doris; Rüsch-Gerdes, Sabine; Richter, Elvira

    2009-06-01

    The new GenoType Mycobacterium tuberculosis drug resistance second line (MTBDRsl) assay (Hain Lifescience, Nehren, Germany) was tested on 106 clinical isolates and directly on 64 sputum specimens for the ability to detect resistance to fluoroquinolones, injectable drugs (amikacin or capreomycin), and ethambutol in Mycobacterium tuberculosis strains. A total of 63 strains harboring fluoroquinolone, amikacin/capreomycin, or ethambutol resistance and 43 fully susceptible strains were comparatively analyzed with the new MTBDRsl assay, by DNA sequencing, and by conventional drug susceptibility testing in liquid and solid media. No discrepancies were obtained in comparison with the DNA sequencing results. Fluoroquinolone resistance was detected in 29 (90.6%) of 32, amikacin/capreomycin resistance was detected in 39/39 (84.8%/86.7%) of 46/45, and ethambutol resistance was detected in 36 (69.2%) of 52 resistant strains. A total of 64 sputum specimens (42 smear positive, 12 scanty, and 10 smear negative) were tested with the new MTBDRsl assay, and the results were compared with those of conventional drug susceptibility testing. Fluoroquinolone resistance was detected in 8 (88.9%) of 9, amikacin/capreomycin resistance was detected in 6/7 (75.0%/87.5%) of 8, and ethambutol resistance was detected in 10 (38.5%) of 26 resistant strains. No mutation was detected in susceptible strains. The new GenoType MTBDRsl assay represents a reliable tool for the detection of fluoroquinolone and amikacin/capreomycin resistance and to a lesser extent also ethambutol resistance. In combination with a molecular test for detection of rifampin and isoniazid resistance, the potential for the detection of extensively resistant tuberculosis within 1 to 2 days can be postulated.

  5. The comparison of genotyping, antibiogram, and antimicrobial resistance genes between carbapenem-susceptible and -resistant Acinetobacter baumannii.

    Science.gov (United States)

    Chen, Chih-Ming; Ke, Se-Chin; Li, Chia-Ru; Chang, Chao-Chin

    2014-12-01

    This study was conducted to explore the epidemiological and molecular differences between carbapenem-susceptible Acinetobacter baumannii (CSAB) and carbapenem-resistant A. baumannii (CRAB) isolates. Thirty-two CSAB and 55 CRAB isolates were collected in 2010. By multilocus sequence typing analysis, 31 (56%) CRAB isolates and 11 (34%) CSAB isolates belonged to ST2. Twenty-one (38%) CRAB isolates, and 4 (13%) CSAB isolates belonged to a new type, ST129. The blaIMP, blaVIM, and blaOXA-58-like were not detected in our study isolates. blaOXA-23 and blaOXA-24/40-like were not detected in all CSAB isolates. On the contrary, blaOXA-23 was detected in 51 (93%) CRAB isolates. Class 1 integron was detected in 19 (35%) CRAB isolates and 8 (25%) CSAB isolates (p>0.05). In conclusion, the ST2 and ST129 were the major sequence types in both CSAB and CRAB isolates. The blaOXA-23 is the primary carbapenem-resistance gene in CRAB isolates from hospitalized patients and the specimens collected from hospital environment.

  6. Phenotypic and genotypic profile of pyrethroid resistance in populations of the mosquito Aedes aegypti from Goiânia, Central West Brazil

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    Francesca Guaracyaba Garcia Chapadense

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION:The mosquito Aedes aegypti has evolved resistance to pyrethroid insecticides. The present study evaluated Ae. aegypti from Goiânia for the resistant phenotype and for mutations associated with resistance.METHODS:Insecticide dose-response bioassays were conducted on mosquitoes descended from field-collected eggs, and polymerase chain reaction (PCR was used to genotype 90 individuals at sites implicated in pyrethroid resistance.RESULTS:All mosquito populations displayed high levels of resistance to deltamethrin, as well as high frequencies of the 1016Ile kdr and 1534Cys kdrmutations.CONCLUSIONS:Aedes aegypti populations in the Goiânia area are highly resistant to deltamethrin, presumably due to high frequencies of kdr(knockdown-resistance mutations.

  7. Development and evaluation of an assay for HIV-1 protease and reverse transcriptase drug resistance genotyping of all major group-M subtypes

    NARCIS (Netherlands)

    Aitken, S.C.; Kliphuis, A.; Wallis, C.L.; Chu, M.L.; Fillekes, Q.; Barth, R.; Stevens, W.B.; Rinke de Wit, T.F.; Schuurman, R.

    2012-01-01

    BACKGROUND: High cost and varying sensitivity for non-B HIV-1 subtypes limits application of current commercial kits for HIV-1 drug resistance genotyping of all major HIV-1 group-M subtypes. OBJECTIVES: Our research aimed to develop and validate an assay specific for all major HIV-1 group-M subtypes

  8. Development and evaluation of an assay for HIV-1 protease and reverse transcriptase drug resistance genotyping of all major group-M subtypes

    NARCIS (Netherlands)

    Aitken, Susan C.; Kliphuis, Aletta; Wallis, Carole L.; Chu, Mei Ling; Fillekes, Quirine; Barth, Roos; Stevens, Wendy; de Wit, Tobias F. Rinke; Schuurman, Rob

    2012-01-01

    Background: High cost and varying sensitivity for non-B HIV-1 subtypes limits application of current commercial kits for HIV-1 drug resistance genotyping of all major HIV-1 group-M subtypes. Objectives: Our research aimed to develop and validate an assay specific for all major HIV-1 group-M subtypes

  9. The impact of genotyping-by-sequencing pipelines on SNP discovery and identification of markers associated verticillium wilt resistance in autotetraploid alfalfa (sedicago sativa l.)

    Science.gov (United States)

    Verticillium wilt (VW) of alfalfa is a soilborne disease that causes severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) was used for mapping lo...

  10. Phenotypic and Genotypic Analysis of Multidrug-Resistant Mycobacterium tuberculosis Isolates from Sudanese Patients

    Science.gov (United States)

    Salih, Mohamed Ahmed; Ali, Manasik; EL-Zaki, Salah-Eldin; Abuzeid, Nadir; Elgadi, Zeinab Abubaker Mohammed; Altayb, Hisham N.; Elegail, Asrar M. A.; Ibrahim, Nuha Y.; Elamin, Bahaeldin K.

    2017-01-01

    Background. Currently, mutations in rpoB, KatG, and rrs genes and inhA promoter were considered to be involved in conferring resistance to rifampicin, isoniazid, and streptomycin in Mycobacterium tuberculosis (MTB). Objective. The aims of this study were to detect the prevalence of first-line tuberculosis (TB) drug resistance among a group of previously treated and newly detected TB patients, to determine the association between prevalence of multidrug resistance (MDR) and demographic information (age and sex), to explain genes correlated with MDR Mycobacterium tuberculosis, and to characterize MTB via 16S ribosomal RNA (16S rRNA) analysis. Methods. A hundred MTB isolates from Sudanese pulmonary TB patients were included in the study. The proportional method of drug susceptibility test was carried out on Löwenstein-Jensen media. Multiplex PCR of rpoB and KatG genes and inhA promoter was conducted; then rrs genes were amplified by conventional PCR and were sequenced. The sequences of the PCR product were compared with known rrs gene sequences in the GenBank database by multiple sequence alignment tools. Result. The prevalence of MDR was 14.7% among old cases and 5.3% among newly diagnosed cases. Conclusion. Mutations in rrs could be considered as a diagnostic marker. PMID:28197340

  11. Serotypes, antimicrobial resistance and genotypes of Streptococcus pneumoniae associated with infections in cancer patients in Brazil.

    Science.gov (United States)

    Cardoso, Nayara Torres; Santos, Bárbara Araújo; Barbosa, André Victor; Superti, Silvana Vargas; Teixeira, Lúcia Martins; Neves, Felipe Piedade Gonçalves

    2017-03-01

    We sought to characterize pneumococcal isolates associated with bacteremia, pneumonia and meningitis in cancer patients and to estimate the coverage of the available pneumococcal vaccines. Fifty isolates recovered from 49 patients attending a cancer reference center over a 1-year period were analyzed. The prevalent serotypes were: 23F (12%), 6A (8%), 3, 4, 20, and 23A (6% each). All isolates were susceptible to chloramphenicol, levofloxacin, rifampicin, and vancomycin. Resistance or reduced susceptibility to penicillin made up 14%, and one isolate was also intermediately resistant to ceftriaxone. The three (6%) erythromycin-resistant isolates presented the M or cMLSB phenotypes and harbored the mef(A/E) gene exclusively or along with the erm(B) gene. Twenty-two (44%) isolates were closely related to 11 international clones, being strongly associated with penicillin non-susceptibility. Combined immunization with the 13-valent conjugate and the 23-valent polysaccharide vaccines might contribute to reduce (76%) the burden of the pneumococcal infections in the population investigated.

  12. Phenotypic and Genotypic Analysis of Multidrug-Resistant Mycobacterium tuberculosis Isolates from Sudanese Patients

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    Solima M. A. Sabeel

    2017-01-01

    Full Text Available Background. Currently, mutations in rpoB, KatG, and rrs genes and inhA promoter were considered to be involved in conferring resistance to rifampicin, isoniazid, and streptomycin in Mycobacterium tuberculosis (MTB. Objective. The aims of this study were to detect the prevalence of first-line tuberculosis (TB drug resistance among a group of previously treated and newly detected TB patients, to determine the association between prevalence of multidrug resistance (MDR and demographic information (age and sex, to explain genes correlated with MDR Mycobacterium tuberculosis, and to characterize MTB via 16S ribosomal RNA (16S rRNA analysis. Methods. A hundred MTB isolates from Sudanese pulmonary TB patients were included in the study. The proportional method of drug susceptibility test was carried out on Löwenstein-Jensen media. Multiplex PCR of rpoB and KatG genes and inhA promoter was conducted; then rrs genes were amplified by conventional PCR and were sequenced. The sequences of the PCR product were compared with known rrs gene sequences in the GenBank database by multiple sequence alignment tools. Result. The prevalence of MDR was 14.7% among old cases and 5.3% among newly diagnosed cases. Conclusion. Mutations in rrs could be considered as a diagnostic marker.

  13. Genotyping-by-sequencing markers facilitate the identification of quantitative trait loci controlling resistance to Penicillium expansum in Malus sieversii

    Science.gov (United States)

    Wisniewski, Michael; Fazio, Gennaro; Burchard, Erik; Gutierrez, Benjamin; Levin, Elena; Droby, Samir

    2017-01-01

    Blue mold caused by Penicillium expansum is the most important postharvest disease of apple worldwide and results in significant financial losses. There are no defined sources of resistance to blue mold in domesticated apple. However, resistance has been described in wild Malus sieversii accessions, including plant introduction (PI)613981. The objective of the present study was to identify the genetic loci controlling resistance to blue mold in this accession. We describe the first quantitative trait loci (QTL) reported in the Rosaceae tribe Maleae conditioning resistance to P. expansum on genetic linkage group 3 (qM-Pe3.1) and linkage group 10 (qM-Pe10.1). These loci were identified in a M.× domestica ‘Royal Gala’ X M. sieversii PI613981 family (GMAL4593) based on blue mold lesion diameter seven days post-inoculation in mature, wounded apple fruit inoculated with P. expansum. Phenotypic analyses were conducted in 169 progeny over a four year period. PI613981 was the source of the resistance allele for qM-Pe3.1, a QTL with a major effect on blue mold resistance, accounting for 27.5% of the experimental variability. The QTL mapped from 67.3 to 74 cM on linkage group 3 of the GMAL4593 genetic linkage map. qM-Pe10.1 mapped from 73.6 to 81.8 cM on linkage group 10. It had less of an effect on resistance, accounting for 14% of the experimental variation. ‘Royal Gala’ was the primary contributor to the resistance effect of this QTL. However, resistance-associated alleles in both parents appeared to contribute to the least square mean blue mold lesion diameter in an additive manner at qM-Pe10.1. A GMAL4593 genetic linkage map composed of simple sequence repeats and ‘Golden Delicious’ single nucleotide polymorphism markers was able to detect qM-Pe10.1, but failed to detect qM-Pe3.1. The subsequent addition of genotyping-by-sequencing markers to the linkage map provided better coverage of the PI613981 genome on linkage group 3 and facilitated discovery of q

  14. Genotyping-by-sequencing markers facilitate the identification of quantitative trait loci controlling resistance to Penicillium expansum in Malus sieversii.

    Science.gov (United States)

    Norelli, John L; Wisniewski, Michael; Fazio, Gennaro; Burchard, Erik; Gutierrez, Benjamin; Levin, Elena; Droby, Samir

    2017-01-01

    Blue mold caused by Penicillium expansum is the most important postharvest disease of apple worldwide and results in significant financial losses. There are no defined sources of resistance to blue mold in domesticated apple. However, resistance has been described in wild Malus sieversii accessions, including plant introduction (PI)613981. The objective of the present study was to identify the genetic loci controlling resistance to blue mold in this accession. We describe the first quantitative trait loci (QTL) reported in the Rosaceae tribe Maleae conditioning resistance to P. expansum on genetic linkage group 3 (qM-Pe3.1) and linkage group 10 (qM-Pe10.1). These loci were identified in a M.× domestica 'Royal Gala' X M. sieversii PI613981 family (GMAL4593) based on blue mold lesion diameter seven days post-inoculation in mature, wounded apple fruit inoculated with P. expansum. Phenotypic analyses were conducted in 169 progeny over a four year period. PI613981 was the source of the resistance allele for qM-Pe3.1, a QTL with a major effect on blue mold resistance, accounting for 27.5% of the experimental variability. The QTL mapped from 67.3 to 74 cM on linkage group 3 of the GMAL4593 genetic linkage map. qM-Pe10.1 mapped from 73.6 to 81.8 cM on linkage group 10. It had less of an effect on resistance, accounting for 14% of the experimental variation. 'Royal Gala' was the primary contributor to the resistance effect of this QTL. However, resistance-associated alleles in both parents appeared to contribute to the least square mean blue mold lesion diameter in an additive manner at qM-Pe10.1. A GMAL4593 genetic linkage map composed of simple sequence repeats and 'Golden Delicious' single nucleotide polymorphism markers was able to detect qM-Pe10.1, but failed to detect qM-Pe3.1. The subsequent addition of genotyping-by-sequencing markers to the linkage map provided better coverage of the PI613981 genome on linkage group 3 and facilitated discovery of qM-Pe3.1. A DNA

  15. Fracture resistance exhibited by endodontically treated and retreated teeth shaped by ProTaper NEXT versus WaveOne: An in vitro study

    Science.gov (United States)

    Khalap, Neha Deepak; Hegde, Vibha; Kokate, Sharad

    2015-01-01

    Aim: To compare the fracture resistance exhibited by teeth after primary endodontic treatment and retreatment. Materials and Methods: One hundred freshly extracted human teeth were selected. 20 samples served as control (untreated). Eighty experimental samples were divided into two groups (n = 40) for instrumentation using rotary Protaper NEXT (PTN) or reciprocating WaveOne (WO) files and obturated using warm lateral compaction. Half of the samples (n = 20) from each group were subjected to a load. The remaining half were subjected to retreatment using Protaper universal retreatment files (RFs) followed by a file larger than the master apical file used in groups 1 and 2 and reobturated. Group A: Control, Group B: PTN + obturation, Group C: WO + obturation, Group D: RF + PTN + obturation and Group E: RF + WO + obturation. The retreatment specimens were also subjected to load and the readings acquired were statistically analyzed. Result: When compared between the groups, control group exhibited the highest fracture resistance (P < 0.01). When multiple tests were performed, Group E exhibited significantly less fracture resistance (P < 0.01). Conclusion: Endodontic treatment and retreatment both results in lowering the fracture resistance of a tooth. PMID:26752838

  16. Fracture resistance exhibited by endodontically treated and retreated teeth shaped by ProTaper NEXT versus WaveOne: An in vitro study

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    Neha Deepak Khalap

    2015-01-01

    Full Text Available Aim: To compare the fracture resistance exhibited by teeth after primary endodontic treatment and retreatment. Materials and Methods: One hundred freshly extracted human teeth were selected. 20 samples served as control (untreated. Eighty experimental samples were divided into two groups (n = 40 for instrumentation using rotary Protaper NEXT (PTN or reciprocating WaveOne (WO files and obturated using warm lateral compaction. Half of the samples (n = 20 from each group were subjected to a load. The remaining half were subjected to retreatment using Protaper universal retreatment files (RFs followed by a file larger than the master apical file used in groups 1 and 2 and reobturated. Group A: Control, Group B: PTN + obturation, Group C: WO + obturation, Group D: RF + PTN + obturation and Group E: RF + WO + obturation. The retreatment specimens were also subjected to load and the readings acquired were statistically analyzed. Result: When compared between the groups, control group exhibited the highest fracture resistance (P < 0.01. When multiple tests were performed, Group E exhibited significantly less fracture resistance (P < 0.01. Conclusion: Endodontic treatment and retreatment both results in lowering the fracture resistance of a tooth.

  17. KPC-Producing Klebsiella pneumoniae Strains That Harbor AAC(6′)-Ib Exhibit Intermediate Resistance to Amikacin

    Science.gov (United States)

    Bremmer, Derek N.; Clancy, Cornelius J.; Press, Ellen G.; Almaghrabi, Reem; Chen, Liang; Doi, Yohei; Nguyen, M. Hong

    2014-01-01

    The aminoglycoside-modifying enzyme AAC(6′)-Ib is common among carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strains. We investigated amikacin (AMK) activity against 20 AAC(6′)-Ib-producing CR-Kp strains. MICs clustered at 16 to 32 μg/ml. By the time-kill study, AMK (1× and 4× the MIC) was bactericidal against 30% and 85% of the strains, respectively. At achievable human serum concentrations, however, the majority of strains showed regrowth, suggesting that AAC(6′)-Ib confers intermediate AMK resistance. AMK and trimethoprim-sulfamethoxazole (TMP-SMX) were synergistic against 90% of the strains, indicating that the combination may overcome resistance. PMID:25288089

  18. Naturally occurring NS3 resistance-associated variants in hepatitis C virus genotype 1: Their relevance for developing countries.

    Science.gov (United States)

    Echeverría, Natalia; Betancour, Gabriela; Gámbaro, Fabiana; Hernández, Nelia; López, Pablo; Chiodi, Daniela; Sánchez, Adriana; Boschi, Susana; Fajardo, Alvaro; Sóñora, Martín; Moratorio, Gonzalo; Cristina, Juan; Moreno, Pilar

    2016-09-02

    Hepatitis C virus (HCV) is a major cause of global morbidity and mortality, with an estimated 130-150 million infected individuals worldwide. HCV is a leading cause of chronic liver diseases including cirrhosis and hepatocellular carcinoma. Current treatment options in developing countries involve pegylated interferon-α and ribavirin as dual therapy or in combination with one or more direct-acting antiviral agents (DAA). The emergence of resistance-associated variants (RAVs) after treatment reveals the great variability of this virus leading to a great difficulty in developing effective antiviral strategies. Baseline RAVs detected in DAA treatment-naïve HCV-infected patients could be of great importance for clinical management and outcome prediction. Although the frequency of naturally occurring HCV NS3 protease inhibitor mutations has been addressed in many countries, there are only a few reports on their prevalence in South America. In this study, we investigated the presence of RAVs in the HCV NS3 serine protease region by analysing a cohort of Uruguayan patients with chronic hepatitis C who had not been treated with any DAAs and compare them with the results found for other South American countries. The results of these studies revealed that naturally occurring mutations conferring resistance to NS3 inhibitors exist in a substantial proportion of Uruguayan treatment-naïve patients infected with HCV genotype 1 enrolled in these studies. The identification of these baseline RAVs could be of great importance for patients' management and outcome prediction in developing countries.

  19. Phenotypic and genotypic detection of methicillin-resistant Staphylococcus aureus in hunting dogs in Maiduguri metropolitan, Borno State, Nigeria

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    Muhammad Mustapha

    2016-05-01

    Full Text Available Aim: To determine the presence of MRSA in hunting dogs in Maiduguri metropolitan. Materials and Methods: Phenotypic methods used includes microscopic technique, colony morphology study, catalase-coagulase tests, and the use of mannitol salt agar test, oxacillin resistance screening agar base, and antibiotic susceptibility testing methods. Genotypic approach was used for deoxyribonucleic acid extraction, and the presence of nuc and mecA gene was detected using polymerase chain reaction (PCR techniques. Results: Examination of 416 swab samples from nasal and perineal region of dogs revealed a total of 79.5% of S. aureus, where 62.5% of the isolates were MRSA. Molecular analysis revealed that 7nuc genes specific for S. aureus from 20 presumptive MRSA assay were all mecA PCR negative. The isolates were sensitive to gentamicin and ciprofloxacin but proved resistant to cefoxitin and oxacillin. Conclusion: High isolation rate of MRSA was found in hunting dogs. Significant level (p<0.05 of MRSA was isolated in the nasal cavity of hunting dogs than its perineum. Only nuc genes were detected from the MRSA isolates.

  20. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

    Science.gov (United States)

    Rodriguez-Auad, Juan Pablo; Rojas-Montes, Othon; Maldonado-Rodriguez, Angelica; Alvarez-Muñoz, Ma. Teresa; Muñoz, Onofre; Torres-Ibarra, Rocio; Vazquez-Rosales, Guillermo

    2015-01-01

    Monitoring antiretroviral therapy using measurements of viral load (VL) and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS) samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM) in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6%) of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings. PMID:26779533

  1. Use of Dried Plasma Spots for HIV-1 Viral Load Determination and Drug Resistance Genotyping in Mexican Patients

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    Juan Pablo Rodriguez-Auad

    2015-01-01

    Full Text Available Monitoring antiretroviral therapy using measurements of viral load (VL and the genotyping of resistance mutations is not routinely performed in low- to middle-income countries because of the high costs of the commercial assays that are used. The analysis of dried plasma spot (DPS samples on filter paper may represent an alternative for resource-limited settings. Therefore, we evaluated the usefulness of analyzing DPS samples to determine VL and identify drug resistance mutations (DRM in a group of HIV-1 patients. The VL was measured from 22 paired plasma and DPS samples. In these samples, the average VL was 4.7 log10 copies/mL in liquid plasma and 4.1 log10 copies/mL in DPS, with a correlation coefficient of R = 0.83. A 1.1 kb fragment of HIV pol could be amplified in 14/22 (63.6% of the DPS samples and the same value was amplified in plasma samples. A collection of ten paired DPS and liquid plasma samples was evaluated for the presence of DRM; an excellent correlation was found in the identification of DRM between the paired samples. All HIV-1 pol sequences that were obtained corresponded to HIV subtype B. The analysis of DPS samples offers an attractive alternative for monitoring ARV therapy in resource-limited settings.

  2. A J integral based method to measure fracture resistance and cohesive laws in materials exhibiting large scale plasticity

    DEFF Research Database (Denmark)

    Sørensen, Bent F.; Goutianos, Stergios

    2014-01-01

    A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non-linear s......A method is developed to extract the fracture resistance and mode I cohesive law of nonlinear elastic-plastic materials using a Double Cantilever Beam (DCB) sandwich specimen loaded with pure bending moments. The method is based on the J integral which is valid for materials having a non...

  3. Genotypic assessment of drug-resistant tuberculosis in Baghdad and other Iraqi provinces using low-cost and low-density DNA microarrays.

    Science.gov (United States)

    Al-Rubaye, Dalal Saleh; Henihan, Grace; Al-Abasly, Ameraa K Abas; Seagar, Amie-Louise; Al-Attraqchi, Azhar Ab F; Schulze, Holger; Hashim, Dhafer Salman; Kamil, Jinan Khalid; Laurenson, Ian F; Bachmann, Till T

    2016-02-01

    We report on a molecular investigation carried out to ascertain the prevalence of drug-resistant tuberculosis (TB) and the specific gene mutations responsible for resistance to rifampicin (RIF) and/or isoniazid (INH) in Iraq. In total, 110 clinical isolates from category II TB cases from Baghdad (58%) and several Iraqi provinces (42%) were analysed using colorimetric, low-cost and low-density (LCD) microarrays (MYCO-Direct and MYCO-Resist LCD array kits) to identify the point mutations responsible for resistance in Mycobacterium tuberculosis isolates. We found 76 patients (69.1%) had resistant strains, of which 40 (36%) were multidrug-resistant (MDR)-TB. Where mono-resistance was identified, it was found to be predominantly to RIF (83%). The most common mutations were rpoB S531L (50%), inhA C15T (25%) and katG S315T (15%). The most common MDR-TB genotypes were rpoB S531L with inhA C15T (60%) and rpoB S531L with katG S315T (20%). Where phenotypic analysis of clinical isolates was also performed, genotypic data were found to show excellent correlation with phenotypic results. Correlation was found between the MYCO-Resist LCD array and GenoType MTBDRplus for detection of resistance to RIF. Our study shows MDR-TB in 36% of category II TB cases in Baghdad and surrounding Iraqi provinces, which reflects the World Health Organization findings based on phenotypic studies. Diagnosis of TB and MDR-TB using culture-based tests is a significant impediment to global TB control. The LCD arrays investigated herein are easy to use, sensitive and specific molecular tools for TB resistance profiling in resource-limited laboratory settings.

  4. Transcriptomic analysis of multidrug-resistant Salmonella enterica serovar Typhimurium isolates that exhibit a tetracycline-induced invasion phenotype

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    Salmonella is a highly prevalent bacterial food-borne disease in the U.S. and is estimated to cause over 1 million cases, 19,000 hospitalizations, and 350 deaths every year. Multidrug-resistant (MDR) Salmonella has emerged as an important food safety concern as it is associated with increased morbi...

  5. Efficacy of aflibercept on exudative age-related macular degeneration in patients exhibiting complete ranibizumab resistance and tachyphylaxis

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    Gokcen Gokce

    Full Text Available ABSTRACT Purpose: The present study compared the efficacy of aflibercept for neovascular age-related macular degeneration (NV-AMD in patients with complete ranibizumab resistance and tachyphylaxis. Methods: Forty-four eyes of 38 neovascular age-related macular degeneration patients were evaluated. Eyes were divided into a complete resistance group (n=23 eyes and tachyphylaxis group (n=21 eyes. Results: After three injections, eight (38.1% patients in the tachyphylaxis group and nine (39.1% in the complete resistance group presented with macular dryness. After the first injection of aflibercept, the mean visual acuity improved significantly in the tachyphylaxis group (p=0.018 but remained unchanged in the complete resistance group (p=0.37. There was a non-significant trend towards improved mean visual acuity in both groups after the second and third injections relative to the acuity at the final visit for ranibizumab treatment. In the tachyphylaxis group, the presence of subfoveal pigmented epithelium detachment (PED decreased significantly after intravitreal aflibercept treatment. Conclusions: Although treatment with aflibercept yielded generally positive anatomical results in both groups, no significant increase in visual acuity was achieved.

  6. Genotyping of methicillin resistant staphylococcus aureus from tertiary care hospitals in Coimbatore, South India

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    Toms John Peedikayil Neetu

    2016-01-01

    Full Text Available Background: Globally, methicillin resistant Staphylococcus aureus (MRSA is one of the most common pathogens that causes hospital- and community-acquired infections. The use of molecular typing methods is essential for determining the origin of the isolates, their clonal relations, and also epidemiological investigations. Objective: The purpose of this study was to determine the prevalence of antibiotic-resistant MRSA investigate the accessory gene regulator (agr and staphylococcal cassette chromosome mec (SCCmec types and perform multilocus sequence typing (MLST. Furthermore, the minimum inhibitory concentration of MRSA isolates was determined for vancomycin and daptomycin. Materials and Methods: Two hundred and fifty-nine MRSA isolates were collected from Tertiary Care Hospitals in Coimbatore. Disk diffusion method was employed to assess the sensitivity of MRSA isolates to selected antibiotics and genetic analysis was performed using SCCmec, agr, and MLST typing by multiplex-polymerase chain reaction strategy. Minimal inhibitory concentration (MIC was determined using Ezy MIC (vancomycin and Biomerieux (daptomycin E-test strip. Results: Of 259 MRSA isolates, 209 (80.7% were confirmed as methicillin resistant. Antibiotic susceptibility pattern revealed that all the MRSA isolates were 100% sensitive to linezolid, rifampicin, teicoplanin, and vancomycin. MIC results showed that of 209 MRSA isolates, 10 were found to be vancomycin intermediate S. aureus and 100% of the MRSA isolates were daptomycin-susceptible. The agr group I and SCCmec Type III were the major type among MRSA isolates. In addition to these MLST typing revealed the prevalence of sequence type (ST 239 (SLV of ST8 among the MRSA isolates. Conclusion: This study confirms that ST239 (Brazilian clone of MRSA is predominant in this region which is responsible for the hospital-acquired MRSA infections. Thus, the study also suggests that vancomycin and daptomycin can still be used as an

  7. The Impact of Genotyping-by-Sequencing Pipelines on SNP Discovery and Identification of Markers Associated with Verticillium Wilt Resistance in Autotetraploid Alfalfa (Medicago sativa L.)

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    Yu, Long-Xi; Zheng, Ping; Bhamidimarri, Suresh; Liu, Xiang-Ping; Main, Dorie

    2017-01-01

    Verticillium wilt (VW) of alfalfa is a soilborne disease causing severe yield loss in alfalfa. To identify molecular markers associated with VW resistance, we used an integrated framework of genome-wide association study (GWAS) with high-throughput genotyping by sequencing (GBS) to identify loci associated with VW resistance in an F1 full-sib alfalfa population. Phenotyping was performed using manual inoculation of the pathogen to cloned plants of each individual and disease severity was scored using a standard scale. Genotyping was done by GBS, followed by genotype calling using three bioinformatics pipelines including the TASSEL-GBS pipeline (TASSEL), the Universal Network Enabled Analysis Kit (UNEAK), and the haplotype-based FreeBayes pipeline (FreeBayes). The resulting numbers of SNPs, marker density, minor allele frequency (MAF) and heterozygosity were compared among the pipelines. The TASSEL pipeline generated more markers with the highest density and MAF, whereas the highest heterozygosity was obtained by the UNEAK pipeline. The FreeBayes pipeline generated tetraploid genotypes, with the least number of markers. SNP markers generated from each pipeline were used independently for marker-trait association. Markers significantly associated with VW resistance identified by each pipeline were compared. Similar marker loci were found on chromosomes 5, 6, and 7, whereas different loci on chromosome 1, 2, 3, and 4 were identified by different pipelines. Most significant markers were located on chromosome 6 and they were identified by all three pipelines. Of those identified, several loci were linked to known genes whose functions are involved in the plants’ resistance to pathogens. Further investigation on these loci and their linked genes would provide insight into understanding molecular mechanisms of VW resistance in alfalfa. Functional markers closely linked to the resistance loci would be useful for MAS to improve alfalfa cultivars with enhanced resistance

  8. DQ High genotypic diversity among methicillin-resistant Staphylococcus pseudintermedius isolated from canine infections in Denmark

    DEFF Research Database (Denmark)

    Damborg, Peter; Moodley, Arshnee; Aalbaek, Bent;

    2016-01-01

    -SCCmec IV and its single-and double-locus variants. These were susceptible to 4-7 of the 22 antibiotics tested, whereas CC71 isolates were susceptible to only 2-5 antibiotics. Clone-specific differences were especially pronounced for fluoroquinolones and aminoglycosides with most CC71 isolates being......-resistant. CC258-SCCmec IV isolates, which emerged in Denmark since 2012, display susceptibility to a wider range of antimicrobials. The isolation of distinct STs in individual dogs over time suggests repeated exposure or short-term genetic evolution of MRSP clones within patients....

  9. Genotypic Analysis of Genes Associated with Independent Resistance and Cross-Resistance to Isoniazid and Ethionamide in Mycobacterium tuberculosis Clinical Isolates.

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    Rueda, Johana; Realpe, Teresa; Mejia, Gloria Isabel; Zapata, Elsa; Rozo, Juan Carlos; Ferro, Beatriz Eugenia; Robledo, Jaime

    2015-12-01

    Ethionamide (ETH) is an antibiotic used for the treatment of multidrug-resistant (MDR) tuberculosis (TB) (MDR-TB), and its use may be limited with the emergence of resistance in the Mycobacterium tuberculosis population. ETH resistance in M. tuberculosis is phenomenon independent or cross related when accompanied with isoniazid (INH) resistance. In most cases, resistance to INH and ETH is explained by mutations in the inhA promoter and in the following genes: katG, ethA, ethR, mshA, ndh, and inhA. We sequenced the above genes in 64 M. tuberculosis isolates (n = 57 ETH-resistant MDR-TB isolates; n = 3 ETH-susceptible MDR-TB isolates; and n = 4 fully susceptible isolates). Each isolate was tested for susceptibility to first- and second-line drugs using the agar proportion method. Mutations were observed in ETH-resistant MDR-TB isolates at the following rates: 100% in katG, 72% in ethA, 45.6% in mshA, 8.7% in ndh, and 33.3% in inhA or its promoter. Of the three ETH-susceptible MDR-TB isolates, all showed mutations in katG; one had a mutation in ethA, and another, in mshA and inhA. Finally, of the four fully susceptible isolates, two showed no detectable mutation in the studied genes, and two had mutations in mshA gene unrelated to the resistance. Mutations not previously reported were found in the ethA, mshA, katG, and ndh genes. The concordance between the phenotypic susceptibility testing to INH and ETH and the sequencing was 1 and 0.45, respectively. Among isolates exhibiting INH resistance, the high frequency of independent resistance and cross-resistance with ETH in the M. tuberculosis isolates suggests the need to confirm the susceptibility to ETH before considering it in the treatment of patients with MDR-TB.

  10. Coagulase-negative staphylococci (CoNS) isolated from ready-to-eat food of animal origin--phenotypic and genotypic antibiotic resistance.

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    Chajęcka-Wierzchowska, Wioleta; Zadernowska, Anna; Nalepa, Beata; Sierpińska, Magda; Łaniewska-Trokenheim, Łucja

    2015-04-01

    The aim of this work was to study the pheno- and genotypical antimicrobial resistance profile of coagulase negative staphylococci (CoNS) isolated from 146 ready-to-eat food of animal origin (cheeses, cured meats, sausages, smoked fishes). 58 strains were isolated, they were classified as Staphylococcus xylosus (n = 29), Staphylococcus epidermidis (n = 16); Staphylococcus lentus (n = 7); Staphylococcus saprophyticus (n = 4); Staphylococcus hyicus (n = 1) and Staphylococcus simulans (n = 1) by phenotypic and genotypic methods. Isolates were tested for resistance to erythromycin, clindamycin, gentamicin, cefoxitin, norfloxacin, ciprofloxacin, tetracycline, tigecycline, rifampicin, nitrofurantoin, linezolid, trimetoprim, sulphamethoxazole/trimethoprim, chloramphenicol, quinupristin/dalfopristin by the disk diffusion method. PCR was used for the detection of antibiotic resistance genes encoding: methicillin resistance--mecA; macrolide resistance--erm(A), erm(B), erm(C), mrs(A/B); efflux proteins tet(K) and tet(L) and ribosomal protection proteins tet(M). For all the tet(M)-positive isolates the presence of conjugative transposons of the Tn916-Tn1545 family was determined. Most of the isolates were resistant to cefoxitin (41.3%) followed by clindamycin (36.2%), tigecycline (24.1%), rifampicin (17.2%) and erythromycin (13.8%). 32.2% staphylococcal isolates were multidrug resistant (MDR). All methicillin resistant staphylococci harboured mecA gene. Isolates, phenotypic resistant to tetracycline, harboured at least one tetracycline resistance determinant on which tet(M) was most frequent. All of the isolates positive for tet(M) genes were positive for the Tn916-Tn1545 -like integrase family gene. In the erythromycin-resistant isolates, the macrolide resistance genes erm(C) or msr(A/B) were present. Although coagulase-negative staphylococci are not classical food poisoning bacteria, its presence in food could be of public health significance due to the possible spread of

  11. Genotyping of Plasmodium falciparum using antigenic polymorphic markers and to study anti-malarial drug resistance markers in malaria endemic areas of Bangladesh

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    Akter Jasmin

    2012-11-01

    Full Text Available Abstract Background In the past many regions of Bangladesh were hyperendemic for malaria. Malaria control in the 1960s to 1970s eliminated malaria from the plains but in the Chittagong Hill Tracts remained a difficult to control reservoir. The Chittagong Hill Tracts have areas with between 1 and 10% annual malaria rates, predominately 90-95% Plasmodium falciparum. In Southeast Asia, multiplicity of infection for hypo-endemic regions has been approximately 1.5. Few studies on the genetic diversity of P. falciparum have been performed in Bangladesh. Anderson et al. performed a study in Khagrachari, northern Chittagong Hill Tracts in 2002 on 203 patients and found that parasites had a multiplicity of infection of 1.3 by MSP-1, MSP-2 and GLURP genotyping. A total of 94% of the isolates had the K76T Pfcrt chloroquine resistant genotype, and 70% showed the N86Y Pfmdr1 genotype. Antifolate drug resistant genotypes were high with 99% and 73% of parasites having two or more mutations at the dhfr or dhps loci. Methods Nested and real-time polymerase chain reaction (PCR methods were used to genotype P. falciparum using antigenic polymorphic markers and to study anti-malarial drug resistance markers in malaria endemic areas of Bangladesh. Results The analysis of polymorphic and drug resistant genotype on 33 paired recrudescent infections after drug treatment in the period 2004 to 2008 in the Chittagong Hill Tracts, which is just prior to countrywide provision of artemisinin combination therapy. Overall the multiplicity of infection for MSP-1 was 2.7 with a slightly smaller parasite diversity post-treatment. The 13 monoclonal infections by both GLURP and MSP-1 were evenly divided between pre- and post-treatment. The MSP-1 MAD block was most frequent in 66 of the samples. The prevalence of the K76T PfCRT chloroquine resistant allele was approximately 82% of the samples, while the resistant Pfmdr1 N86Y was present in 33% of the samples. Interestingly, the post

  12. Comparative transcriptome profiling of the early response to Magnaporthe oryzae in durable resistant vs susceptible rice (Oryza sativa L. genotypes.

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    Paolo Bagnaresi

    Full Text Available Durable resistance to blast, the most significant fungal disease of rice, represents an agronomically relevant character. Gigante Vercelli (GV and Vialone Nano (VN are two old temperate japonica Italian rice cultivars with contrasting response to blast infection: GV displays durable and broad resistance while VN is highly susceptible. RNA-seq was used to dissect the early molecular processes deployed during the resistance response of GV at 24 h after blast inoculation. Differential gene expression analysis identified 1,070 and 1,484 modulated genes, of which 726 and 699 were up regulated in response to infection in GV and VN, respectively. Gene ontology (GO enrichment analyses revealed a set of GO terms enriched in both varieties but, despite this commonality, the gene sets contributing to common GO enriched terms were dissimilar. The expression patterns of genes grouped in GV-specific enriched GO terms were examined in detail including at the transcript isoform level. GV exhibited a dramatic up-regulation of genes encoding diterpene phytoalexin biosynthetic enzymes, flavin-containing monooxygenase, class I chitinase and glycosyl hydrolase 17. The sensitivity and high dynamic range of RNA-seq allowed the identification of genes critically involved in conferring GV resistance during the early steps of defence perception-signalling. These included chitin oligosaccharides sensing factors, wall associated kinases, MAPK cascades and WRKY transcription factors. Candidate genes with expression patterns consistent with a potential role as GV-specific functional resistance (R gene(s were also identified. This first application of RNA-seq to dissect durable blast resistance supports a crucial role of the prompt induction of a battery of responses including defence-related genes as well as members of gene families involved in signalling and pathogen-related gene expression regulation.

  13. New patterns of methicillin-resistant Staphylococcus aureus (MRSA) clones, community-associated MRSA genotypes behave like healthcare-associated MRSA genotypes within hospitals, Argentina.

    Science.gov (United States)

    Egea, Ana L; Gagetti, Paula; Lamberghini, Ricardo; Faccone, Diego; Lucero, Celeste; Vindel, Ana; Tosoroni, Dario; Garnero, Analía; Saka, Hector A; Galas, Marcelo; Bocco, José L; Corso, Alejandra; Sola, Claudia

    2014-11-01

    Methicillin-resistant Staphylococcus aureus (MRSA) burden is increasing worldwide in hospitals [healthcare-associated (HA)-MRSA] and in communities [community-associated (CA)-MRSA]. However, the impact of CA-MRSA within hospitals remains limited, particularly in Latin America. A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross-sectional, multicenter study (Nov-2009). This work involved healthcare-onset infections-(HAHO, >48 hospitalization hours) and community-onset (CO) infections [including both, infections (HACO) in patients with healthcare-associated risk-factors (HRFs) and infections (CACO) in those without HRFs]. MRSA strains were genetically typed as CA-MRSA and HA-MRSA genotypes (CA-MRSAG and HA-MRSAG) by SCCmec- and spa-typing, PFGE, MLST and virulence genes profile by PCR. Considering all isolates, 63% were from CO-infections and 55% were MRSA [39% CA-MRSAG and 16% HA-MRSAG]. A significantly higher MRSA proportion among CO- than HAHO-S. aureus infections was detected (58% vs 49%); mainly in children (62% vs 43%). The CA-MRSAG/HA-MRSAG have accounted for 16%/33% of HAHO-, 39%/13% of HACO- and 60.5%/0% of CACO-infections. Regarding the epidemiological associations identified in multivariate models for patients with healthcare-onset CA-MRSAG infections, CA-MRSAG behave like HA-MRSAG within hospitals but children were the highest risk group for healthcare-onset CA-MRSAG infections. Most CA-MRSAG belonged to two major clones: PFGE-type N-ST30-SCCmecIVc-t019-PVL(+) and PFGE-type I-ST5-IV-SCCmecIVa-t311-PVL(+) (45% each). The ST5-IV-PVL(+)/ST30-IV-PVL(+) clones have caused 31%/33% of all infections, 20%/4% of HAHO-, 43%/23% of HACO- and 35%/60% of CACO- infections, with significant differences by age groups (children/adults) and geographical regions. Importantly, an isolate belonging to USA300-0114-(ST8-SCCmecIVa-spat008-PVL(+)-ACME(+)) was detected

  14. Simultaneous detection of hepatitis B virus genotypes and mutations associated with resistance to lamivudine, adefovir, and telbivudine by the polymerase chain reaction-ligase detection reaction

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    Yong-Zhong Wang

    2011-12-01

    Full Text Available OBJECTIVES: Detection of mutations associated to nucleos(tide analogs and hepatitis B virus (HBV genotyping are essential for monitoring treatment of HBV infection. We developed a multiplex polymerase chain reaction-ligase detection reaction (PCR-LDR assay for the rapid detection of HBV genotypes and mutations associated with lamivudine, adefovir, and telbivudine resistance in HBV-infected patients. METHODS: HBV templates were amplified by PCR, followed by LDR and electrophoresis on a sequencer. The assay was evaluated using plasmids that contained wild-type or mutant HBV sequences and 216 clinical samples. RESULTS: The PCR-LDR assay and sequencing gave comparable results for 158 of the 216 samples (73.1% with respect to mutation detection and genotyping. Complete agreement between the two methods was observed for all the samples (100% at codon 180 and codon 204. Concordant results were observed for 99.4% of the 158 samples at codon 181 and 98.7% at codon 236. The genotyping results were completely concordant between the PCR-LDR assay and sequencing. The PCR-LDR assay could detect a proportion of 1% mutant plasmid in a background of wild-type plasmid. CONCLUSION: The PCR-LDR assay is sensitive and specific for detection of HBV genotypes and drug resistance mutations, and could be helpful for decision making in the treatment of HBV infection.

  15. Integrase inhibitor (INI) genotypic resistance in treatment-naive and raltegravir-experienced patients infected with diverse HIV-1 clades

    Science.gov (United States)

    Doyle, Tomas; Dunn, David T.; Ceccherini-Silberstein, Francesca; De Mendoza, Carmen; Garcia, Frederico; Smit, Erasmus; Fearnhill, Esther; Marcelin, Anne-Genevieve; Martinez-Picado, Javier; Kaiser, Rolf; Geretti, Anna Maria

    2015-01-01

    Objectives The aim of this study was to characterize the prevalence and patterns of genotypic integrase inhibitor (INI) resistance in relation to HIV-1 clade. Methods The cohort comprised 533 INI-naive subjects and 255 raltegravir recipients with viraemia who underwent integrase sequencing in routine care across Europe, including 134/533 (25.1%) and 46/255 (18.0%), respectively, with non-B clades (A, C, D, F, G, CRF01, CRF02, other CRFs, complex). Results No major INI resistance-associated mutations (RAMs) occurred in INI-naive subjects. Among raltegravir recipients with viraemia (median 3523 HIV-1 RNA copies/mL), 113/255 (44.3%) had one or more major INI RAMs, most commonly N155H (45/255, 17.6%), Q148H/R/K + G140S/A (35/255, 13.7%) and Y143R/C/H (12/255, 4.7%). In addition, four (1.6%) raltegravir recipients showed novel mutations at recognized resistance sites (E92A, S147I, N155D, N155Q) and novel mutations at other integrase positions that were statistically associated with raltegravir exposure (K159Q/R, I161L/M/T/V, E170A/G). Comparing subtype B with non-B clades, Q148H/R/K occurred in 42/209 (20.1%) versus 2/46 (4.3%) subjects (P = 0.009) and G140S/A occurred in 36/209 (17.2%) versus 1/46 (2.2%) subjects (P = 0.005). Intermediate- to high-level cross-resistance to twice-daily dolutegravir was predicted in 40/255 (15.7%) subjects, more commonly in subtype B versus non-B clades (39/209, 18.7% versus 1/46, 2.2%; P = 0.003). A glycine (G) to serine (S) substitution at integrase position 140 required one nucleotide change in subtype B and two nucleotide changes in all non-B clades. Conclusions No major INI resistance mutations occurred in INI-naive subjects. Reduced occurrence of Q148H/R/K + G140S/A was seen in non-B clades versus subtype B, and was explained by the higher genetic barrier to the G140S mutation observed in all non-B clades analysed. PMID:26311843

  16. Genotypic and phenotypic characteristics of multidrug-resistant hepatitis B virus infection in Chineses hepatitis B patients

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    Yan LIU

    2012-06-01

    Full Text Available Objective  To analyze the genotypic and phenotypic characteristics of multidrug-resistant hepatitis B virus (MDR HBV infection in a large cohort of Chinese hepatitis B patients who had undergone long-term sequential nucleos(tide analogs (NAs treatment. Methods  NAs-resistance-associated mutation patterns and frequency in HBV reverse-transcriptase (RT region were analyzed in 11 800 patients with chronic HBV infection. The MDR HBV strains from 46 patients were further identified by PCR direct sequencing and clonal sequencing (≥20 clones/sample. In vitrophenotypic resistance assay was used to investigate the inhibitory effect of combined use of nucleoside and nucleotide analogs on replication capacity of MDR HBV strains. Influence of clinical antiviral schedules on the development and control of MDR HBV infection was further analyzed. Results  (1 HBV NAs-resistant mutations were detected in the 3658 (31.0% of 11800 tested patients, lamivudine (LAM-, adefovir (ADV-, entecavir (ETV-, and telbivudine (LdT-resistant mutations were detected in 2592 (70.9%, 665 (18.2%, 293 (8.0%, and 62 (1.7% patients, respectivel y. In addition, MDR mutations resistant to both nucleoside and nucleotide analogs were detected in 46 (1.3% patients. (2 Clonal sequencing showed that 40 out of 46 MDR samples harbored mutations in the same HBV genome, and MDR mutations in the other 6 were in individual HBV genomes. Fifteen mutational patterns of MDR HBV strains were detected, including 10 both LAM-/LdT-and ADV-resistant mutations and 5 both ETV-and ADV-resistant mutations. (3 In vitrophenotypic analysis showed that combination use of ETV or LAM plus ADV efficiently inhibited the replication capacity of rtL180M+M204V+S202G+A181V MDR strain in HepG2 cells, whereas the synergistic inhibitory effect was not observed in the wild-type strain. (4 Clinical drug usage showed that MDR HBV infection mainly emerged in patients receiving long-term sequential NAs therapy. Among them

  17. Cobra ( Naja spp. ) nicotinic acetylcholine receptor exhibits resistance to Erabu sea snake ( Laticauda semifasciata) short-chain alpha-neurotoxin.

    Science.gov (United States)

    Takacs, Zoltan; Wilhelmsen, Kirk C; Sorota, Steve

    2004-05-01

    Snake alpha-neutotoxins of Elapidae venoms are grouped into two structural classes, short-chain and long-chain alpha-neutotoxins. While these two classes share many chemical and biological characteristics, there are also distinct dissimilarities between them, including their binding site on the nicotinic acetylcholine receptor (nAChR), specificity among species of Chordata, and the associated pharmacological effects. In the present study we test the hypothesis that structural motifs that evolved to confer natural resistance against conspecific long-chain alpha-neurotoxins in Elapidae snakes also interfere with the biological action of short-chain alpha-neurotoxins. We expressed functional nAChRs that contains segments or single residues of the Elapidae nAChR ligand binding domain and tested the effect of short-chain alpha-neurotoxin erabutoxin-a (ETX-a) from the Erabu sea snake Laticauda semifasciata on the acetylcholine-induced currents as measured by two-microelectrode voltage clamp. Our results show that the Elapidae nAChR alpha subunit segment T(154)-L(208) ligand binding domain has an inhibitory effect on the pharmacological action of ETX-a. This effect is primarily attributed to the presence of glycosylation at position N(189). If the glycosylation is removed from the T(154)-L(208) segment, the nAChR will be inhibited, however, to a lesser extent than seen in the mouse. This effect correlates with the variations in alpha-neurotoxin sensitivity of different species and, importantly, reflects the evolutionary conservation of the binding site on the nAChR polypeptide backbone per se. Phylogenetic analysis of alpha-neurotoxin resistance suggests that alpha-neurotoxin-resistant nAChR evolved first, which permitted the evolution of snake venom alpha-neurotoxins. A model describing alpha-neurotoxin resistance in Elapidae snakes is presented.

  18. A study of Salmonella in pigs from birth to carcass: serotypes, genotypes, antibiotic resistance and virulence profiles.

    Science.gov (United States)

    Bolton, Declan J; Ivory, Claire; McDowell, David

    2013-01-01

    associated with non-SGI1 Salmonella strains. The continued emergence of non-DT104 S. Typhimurium isolates exhibiting multidrug resistance is a cause for concern as is the persistence of highly virulent Salmonella strains in the abattoir environment.

  19. Reaction of faba bean genotypes to Rhizoctonia solani and resistance stability Reação de genótipos de fava a Rhizoctonia solani e estabilidade da resistência

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    Iraildes P Assunção

    2011-12-01

    Full Text Available The production of faba bean (Phaseolus lunatus is limited due to the occurrence of Rhizoctonia canker, caused by the fungus Rhizoctonia solani. In order to select materials with potential for use in faba beans breeding programs and/or disease integrated management, 72 genotypes were evaluated and also stability of the disease resistance in relation to different pathogen isolates, inoculum densities and soil type. The seeds were sown in soil infested with the pathogen by the addition of colonized substrate (rice grains. The evaluation of genotypes was done after 15 days, using a note scale to discriminate the genotypes into five reaction classes. None of the 72 genotypes showed immunity to R. solani and only four genotypes (F-42, F-49, F-53 and F-58 behaved as highly resistant. The reactions presented by these genotypes varied according to the R. solani isolate, inoculum density and soil used. The genotype F-58 showed more stable resistance to pathogen isolates and inoculum densities. The genotype F-53 showed resistance stability in soils collected in different locations, remaining highly resistant in all situations. The genotype F-58 did not show high resistance to only one tested soil. Therefore, the genotypes F-58 and F-53 are promising sources of resistance to R. solani and should be indicated in areas infested by the pathogen.A produção de fava (Phaseolus lunatus é limitada pela ocorrência da rizoctoniose, causada pelo fungo Rhizoctonia solani. Visando selecionar materiais com potencial de utilização nos programas de melhoramento e/ou no manejo integrado da doença, foram avaliados 72 genótipos de fava e verificada a estabilidade da resistência em relação a diferentes isolados do patógeno, densidades de inóculo e tipos de solo. As sementes foram plantadas em solo infestado com o patógeno pela incorporação de substrato (grãos de arroz colonizado. A avaliação dos genótipos foi realizada após 15 dias, com o auxílio de

  20. Research on Service Life of Flame Resistant Materials in the Exhibition Hall by the Use of Mechanical Method of the Meso Damage Mechanics

    Directory of Open Access Journals (Sweden)

    Zhang Junzhu

    2015-01-01

    Full Text Available The population in the exhibition hall is relatively dense, and fire incidents often occur, so the existence of flame resistant materials is very important. The flame resistant materials are used to analyze the museums, art galleries, science and technology museums and other exhibition halls. Taking two kinds of flame resistant materials, namely, Mg(OH2 and Al(OH3 as an example, this paper establishes a model of meso damage mechanics by the use of mechanical method of the meso damage mechanics, and researches the macro mechanical properties of the thermal insulation materials and decorative materials so as to predict its service life. This research finds that the use of two kinds of flame resistant materials, namely, Mg(OH2 and Al(OH3 can improve the elasticity modulus of the thermal insulation materials and decorative materials used in the construction, so that its macro mechanical properties can have a significant improvement, and its service life can also have a significant improvement after adding flame retardant materials.

  1. Avoidance of Linkage Drag Between Blast Resistance Gene and the QTL Conditioning Spikelet Fertility Based on Genotype Selection Against Heading Date in Rice

    Institute of Scientific and Technical Information of China (English)

    LIU Wen-qiang; FAN Ye-yang; CHEN Jie; SHI Yong-feng; WU Jian-li

    2009-01-01

    Previous study showed that a linkage drag between a blast resistance gene Pi25(t) and QTLs conditioning spikelet fertility (qSF-6) and number of filled grains per panicle (qNFGP-6) was detected on the short arm of chromosome 6. A larger population was used for further verification, and the results confirmed the linkage drag between the blast resistance gene and QTL conditioning spikelet fertility, other than QTL conditioning number of filled grains per panicle. Breakdown or avoidance of the linkage drag could be achieved by selection against the genotype background of a heading-date gene (qHD-7) that resided in the region between RM2 and RM214 on chromosome 7. For further validation, two lines with almost identical genotypes on all chromosomal regions except the Pi25(t) region on chromosome 6 were chosen to develop a new population. The results showed that qSF-6 could be further subdivided into qSF-6-1 and qSF-6-2. When the genotype of the region between RM2 and RM214 was from rice variety Zhong 156, the linkage drag between Pi25(t) and qSF-6-2 was detected and the allele of qSF-6-2 from rice variety Gumei 2 reduced the spikelet fertility. When the genotype of the region between RM2 and RM214 was from Gumei 2, no linkage drag was detected. This indicates that the linkage drag between the blast resistance gene and the QTL conditioning spikelet fertility could be broken down or avoided under a certain background genotype selection against heading-date and provides a marker aided solution for high level of blast resistance and yield breeding in rice and other crops as well.

  2. VacA and cagA genotypes status and antimicrobial resistance properties of Helicobacter pylori strains isolated from meat products in Isfahan province, Iran.

    Science.gov (United States)

    Gilani, A; Razavilar, V; Rokni, N; Rahimi, E

    2017-01-01

    Although Helicobacter pylori has a significant impact on the occurrence of severe clinical syndromes, its exact ways of transmission and origin have not been identified. According to the results of some previously published articles, foods with animal origins play a substantial role in the transmission of H. pylori to humans. The present investigation was carried out to study the vacuolating cytotoxin A (vacA) and cytotoxin associated gene A (cagA) genotypes status and antibiotic resistance properties of H. pylori strains recovered from minced-meat and hamburger samples. A total of 150 meat product samples were collected from supermarkets. All samples were cultured and the susceptive colonies were then subjected to nested-PCR, PCR-based genotyping and disk diffusion methods. 11 out of 150 samples (7.33%) were positive for H. pylori. All the isolates were further identified using the nested-PCR assay. Prevalence of H. pylori in hamburger and minced-meat samples was 1.42% and 12.5%, respectively. S1a, m1a and cagA were the most commonly detected genotypes. The most commonly detected combined genotypes in the H. pylori strains of minced-meat were s1am1a (10%), s1am1b (10%) and s2m1a (10%). Helicobacter pylori strains of meat products harbored the highest levels of resistance against ampicillin (90.90%), erythromycin (72.72%), amoxicillin (72.72%), trimethoprim (63.63%), tetracycline (63.63%), and clarithromycin (63.63%). Hamburger and minced-meat samples may be the sources of virulent and resistant strains of H. pylori. Meat products are possible sources of resistant and virulent strains of H. pylori similar to those vacA and cagA genotypes. Using healthy raw materials and observation of personal hygiene can reduce the risk of H. pylori in meat products.

  3. Cry3Bb1-Resistant Western Corn Rootworm, Diabrotica virgifera virgifera (LeConte) Does Not Exhibit Cross-Resistance to DvSnf7 dsRNA

    Science.gov (United States)

    Khajuria, Chitvan; Pleau, Michael; Ilagan, Oliver; Chen, Mao; Jiang, Changjian; Price, Paula; McNulty, Brian; Clark, Thomas; Head, Graham

    2017-01-01

    Background and Methodology There is a continuing need to express new insect control compounds in transgenic maize against western corn rootworm, Diabrotica virgifera virgifera (LeConte) (WCR). In this study three experiments were conducted to determine cross-resistance between the new insecticidal DvSnf7 dsRNA, and Bacillus thuringiensis (Bt) Cry3Bb1; used to control WCR since 2003, with field-evolved resistance being reported. Laboratory susceptible and Cry3Bb1-resistant WCR were evaluated against DvSnf7 dsRNA in larval diet-incorporation bioassays. Additionally, the susceptibility of seven field and one field-derived WCR populations to DvSnf7 (and Cry3Bb1) was assessed in larval diet-overlay bioassays. Finally, beetle emergence of laboratory susceptible and Cry3Bb1-resistant WCR was evaluated with maize plants in the greenhouse expressing Cry3Bb1, Cry34Ab1/Cry35Ab1, or DvSnf7 dsRNA singly, or in combination. Principal Findings and Conclusions The Cry3Bb1-resistant colony had slight but significantly (2.7-fold; PIRM tool against WCR that will increase the durability of these Bt proteins. These results also illustrate the importance of using appropriate bioassay methods when characterizing field-evolved resistant WCR populations. PMID:28060922

  4. Compromised Photosynthetic Electron Flow and H2O2 Generation Correlate with Genotype-Specific Stomatal Dysfunctions during Resistance against Powdery Mildew in Oats.

    Science.gov (United States)

    Sánchez-Martín, Javier; Montilla-Bascón, Gracia; Mur, Luis A J; Rubiales, Diego; Prats, Elena

    2016-01-01

    Stomatal dysfunction known as "locking" has been linked to the elicitation of a hypersensitive response (HR) following attack of fungal pathogens in cereals. We here assess how spatial and temporal patterns of different resistance mechanisms, such as HR and penetration resistance influence stomatal and photosynthetic parameters in oat (Avena sativa) and the possible involvement of hydrogen peroxide (H2O2) in the dysfunctions observed. Four oat cultivars with differential resistance responses (i.e., penetration resistance, early and late HR) to powdery mildew (Blumeria graminis f. sp. avenae, Bga) were used. Results demonstrated that stomatal dysfunctions were genotype but not response-type dependent since genotypes with similar resistance responses when assessed histologically showed very different locking patterns. Maximum quantum yield (Fv/Fm) of photosystem II were compromised in most Bga-oat interactions and photoinhibition increased. However, the extent of the photosynthetic alterations was not directly related to the extent of HR. H2O2 generation is triggered during the execution of resistance responses and can influence stomatal function. Artificially increasing H2O2 by exposing plants to increased light intensity further reduced Fv/Fm ratios and augmented the patterns of stomatal dysfunctions previously observed. The latter results suggest that the observed dysfunctions and hence a cost of resistance may be linked with oxidative stress occurring during defense induced photosynthetic disruption.

  5. Defense Responses to Mycotoxin-Producing Fungi Fusarium proliferatum, F. subglutinans, and Aspergillus flavus in Kernels of Susceptible and Resistant Maize Genotypes.

    Science.gov (United States)

    Lanubile, Alessandra; Maschietto, Valentina; De Leonardis, Silvana; Battilani, Paola; Paciolla, Costantino; Marocco, Adriano

    2015-05-01

    Developing kernels of resistant and susceptible maize genotypes were inoculated with Fusarium proliferatum, F. subglutinans, and Aspergillus flavus. Selected defense systems were investigated using real-time reverse transcription-polymerase chain reaction to monitor the expression of pathogenesis-related (PR) genes (PR1, PR5, PRm3, PRm6) and genes protective from oxidative stress (peroxidase, catalase, superoxide dismutase and ascorbate peroxidase) at 72 h postinoculation. The study was also extended to the analysis of the ascorbate-glutathione cycle and catalase, superoxide dismutase, and cytosolic and wall peroxidases enzymes. Furthermore, the hydrogen peroxide and malondialdehyde contents were studied to evaluate the oxidation level. Higher gene expression and enzymatic activities were observed in uninoculated kernels of resistant line, conferring a major readiness to the pathogen attack. Moreover expression values of PR genes remained higher in the resistant line after inoculation, demonstrating a potentiated response to the pathogen invasions. In contrast, reactive oxygen species-scavenging genes were strongly induced in the susceptible line only after pathogen inoculation, although their enzymatic activity was higher in the resistant line. Our data provide an important basis for further investigation of defense gene functions in developing kernels in order to improve resistance to fungal pathogens. Maize genotypes with overexpressed resistance traits could be profitably utilized in breeding programs focused on resistance to pathogens and grain safety.

  6. Genotyping of methicillin-resistant Staphylococcus aureus isolates obtained in the Northeast region of Brazil

    Directory of Open Access Journals (Sweden)

    F.C. de Sousa-Junior

    2009-10-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA is a major agent of hospital infections worldwide. In Brazil, a multiresistant MRSA lineage (ST239-SCCmecIIIA, the so-called Brazilian epidemic clone (BEC, has predominated in all regions. However, an increase in nosocomial infections caused by non-multiresistant MRSA clones has recently been observed. In the present study, 45 clinical isolates of MRSA obtained from a university hospital located in Natal city, Brazil, were identified by standard laboratory methods and molecularly characterized using staphylococcal chromosome cassette mec (SCCmec typing and pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was carried out using CLSI methods. The MRSA isolates studied displayed a total of 8 different pulsed-field gel electrophoresis patterns (types A to H with predominance (73% of pattern A (BEC-related. However, MRSA harboring SCCmec type IV were also identified, 3 (7% of which were genetically related to the pediatric clone - USA800 (ST5-SCCmecIV. In addition, we found a considerable genetic diversity within BEC isolates. MRSA displaying SCCmecIV are frequently susceptible to the majority of non-β-lactam antibiotics. However, emergence of multiresistant variants of USA800 was detected.

  7. Single-nucleotide polymorphism genotyping identifies a locally endemic clone of methicillin-resistant Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Ulrich Nübel

    Full Text Available We developed, tested, and applied a TaqMan real-time PCR assay for interrogation of three single-nucleotide polymorphisms that differentiate a clade (termed 't003-X' within the radiation of methicillin-resistant Staphylococcus aureus (MRSA ST225. The TaqMan assay achieved 98% typeability and results were fully concordant with DNA sequencing. By applying this assay to 305 ST225 isolates from an international collection, we demonstrate that clade t003-X is endemic in a single acute-care hospital in Germany at least since 2006, where it has caused a substantial proportion of infections. The strain was also detected in another hospital located 16 kilometers away. Strikingly, however, clade t003-X was not found in 62 other hospitals throughout Germany nor among isolates from other countries, and, hence, displayed a very restricted geographical distribution. Consequently, our results show that SNP-typing may be useful to identify and track MRSA clones that are specific to individual healthcare institutions. In contrast, the spatial dissemination pattern observed here had not been resolved by other typing procedures, including multilocus sequence typing (MLST, spa typing, DNA macrorestriction, and multilocus variable-number tandem repeat analysis (MLVA.

  8. Identification of Clonal Clusters of Klebsiella pneumoniae Isolates from Chennai by Extended Spectrum Beta Lactamase Genotyping and Antibiotic Resistance Phenotyping Analysis

    Directory of Open Access Journals (Sweden)

    C. Kamatchi

    2009-01-01

    Full Text Available Problem statement: An increased resistance to antibiotics has been reported in Klebsiella pneumoniae, an opportunistic gram negative pathogen belonging to Entrobacteraceae due to the evolution and spread of plasmid encoded extended spectrum beta lactamases and other genes conferring cross-resistance to other antibiotics. This is of concern due to the increasing cost of antibiotic treatment and the spread of multidrug resistance to more pathogenic microorganisms. This study was undertaken to analyze the extent of the problem, to identify the most prevalent MDR isolates of Klebsiella pneumoniae in Chennai and to identify new plant based drugs. Approach: About 188 clinical isolates of Klebsiella pneumoniae were collected from Chennai during the period Nov. 2007-Oct. 2008 and their resistance to different groups of antibiotics were analyzed. These isolates were further characterized by molecular studies to identify the ESBL genes conferring the resistance phenotype. Plant extracts were tested against the MDR isolates to identify new treatment methods. Results: Our results showed that the combination therapy of clavulanic acid with cephalosporins and fluroroquinolones-norfloxacin and ciprofloxacin were the most effective antibiotics for treatment of Klebsiella pneumoniae infections. However resistance to clavulanic acid was increasing among the isolates (17%. All the isolates harbored a plasmid containing one or more of the genes for ESBL resistance. Plasmid isolation from the Isolates followed by ESBL PCR genotyping showed that CTX-M was present in 75 % isolates and TEM in 73% isolates either alone or in combination with the other ESBL genes. SHV ESBL type was present only in 42% of isolates. We identified 4 presumptive clonal spreads which were likely to be prevalent in India by clustering based on ESBL genotypic and antibiotic resistance. The isolates with both SHV and CTX were correlated with the

  9. Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.

    Science.gov (United States)

    Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

    2014-06-01

    Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants.

  10. Cunninghamella bertholletiae exhibits increased resistance to human neutrophils with or without antifungal agents as compared to Rhizopus spp.

    Science.gov (United States)

    Simitsopoulou, Maria; Georgiadou, Elpiniki; Walsh, Thomas J; Roilides, Emmanuel

    2010-08-01

    Among Zygomycetes, Cunninghamella bertholletiae occurs less frequently as the etiologic agent of human disease but causes more aggressive, refractory, and fatal infections despite antifungal therapy. Little is known about the differential innate host response against Cunninghamella and other Zygomycetes in the presence of antifungal agents. We therefore studied the activity of human neutrophils (PMNs) alone or in combination with caspofungin, posaconazole (PSC), and voriconazole (VRC) against hyphae of Rhizopus oryzae, Rhizopus microsporus and C. bertholletiae. Hyphal damage was measured by XTT metabolic assay and release of IL-6, IL-8 and TNF-alpha from PMNs by ELISA. Cunninghamella bertholletiae was more resistant to PMN-induced hyphal damage than either Rhizopus spp. at effector:target (E:T) ratios of 1:1, 5:1 and 10:1 (P Rhizopus spp. (P < 0.01). No IL-6 was released from PMNs exposed to the three Zygomycetes. In comparison to R. oryzae and R. microsporus, C. bertholletiae is more resistant to PMN-induced hyphal damage with or without antifungal therapy and is more capable of suppressing release of IL-8.

  11. Occurrence, Virulence Factors, Antimicrobial Resistance, and Genotyping of Staphylococcus aureus Strains Isolated from Chicken Products and Humans.

    Science.gov (United States)

    El Bayomi, Rasha M; Ahmed, Heba A; Awadallah, Maysa A I; Mohsen, Rasha A; Abd El-Ghafar, Abeer E; Abdelrahman, Mahmoud A

    2016-03-01

    Staphylococcus aureus in food is a consequence of inadequate hygienic handling and processing, posing a potential risk to public health. The current study aimed to characterize virulence factors, as well as antimicrobial resistance of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) isolated from retail chicken products and hand swabs from vendors in Egypt. In addition, genetic relatedness of the isolates from chicken and humans was evaluated by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using protein A as a target. A total of 110 samples were collected from chicken products (n = 80) and vendors (n = 30). Overall, 30 (37.5%) chicken products samples were positive for S. aureus, whereas hand swabs from meat handlers revealed that 18 (60%) were positive. Ten MRSA strains were characterized by the presence of the mecA gene, comprising seven isolates from chicken and three from humans. Virulence-associated factors were evaluated by PCR, revealing that 31.3% of S. aureus isolates harbored the Panton-Valentine leukocidin (PVL) gene, whereas 10.4% were positive for the sea and sed genes each, and only two isolates were positive for γ-hemolysin-associated gene. Genotyping using spa PCR-RFLP showed identical restriction banding patterns of MRSA isolates of human and chicken meat origin, indicating the genetic relatedness of the isolates. To the best of our knowledge, this is the first study to characterize PVL-positive MRSA from chicken products and to utilize spa-RFLP for evaluating the genetic relatedness between MRSA of human and chicken origin in Egypt.

  12. Analysis of HBV genotype, drug resistant mutations, and pre-core/basal core promoter mutations in Korean patients with acute hepatitis B.

    Science.gov (United States)

    Lee, Jong Ho; Hong, Sun Pyo; Jang, Eun Sun; Park, Sang Jong; Hwang, Seong Gyu; Kang, Sook-Kyoung; Jeong, Sook-Hyang

    2015-06-01

    Acute hepatitis B, caused by hepatitis B virus (HBV) strains with drug resistant mutations or pre-core/basal core promoter (PC/BCP) mutations, is a public health concern, because this infection is often associated with poor disease outcome or difficulty in therapeutic choice. The HBV genotype, the prevalence of drug resistant mutations, and PC/BCP mutations in Korean patients with acute hepatitis B were studied. From 2006 to 2008, 36 patients with acute hepatitis B were enrolled prospectively in four general hospitals. Among them, 20 showed detectable HBV DNA (median value was 4.8 log copies/mL). HBV genotyping and analysis of HBV mutations that conferred resistance against lamivudine, adefovir, or entecavir and of PC/BCP mutations were performed using highly sensitive restriction fragment mass polymorphism (RFMP) analysis. All 20 patients were infected with HBV genotype C, which causes almost all cases of chronic hepatitis B in Korea. No patient showed mutations that conferred resistance against lamivudine (L180M, M204V/I), adefovir (A181T, N236S), or entecavir (I169M, A184T/V, S202I/G, M250V/I/L). However, four patients had BCP mutations, and two had PC mutations. Platelet counts were significantly lower in the four patients with PC/BCP mutations compared to those with wild type. In this study, all acute hepatitis B patients had genotype C HBV strains with no drug resistant mutations. However, 20% showed PC/BCP mutations. This highlights the need for further study on the significance of PC/BCP mutations.

  13. Tumors initiated by constitutive Cdk2 activation exhibit transforming growth factor beta resistance and acquire paracrine mitogenic stimulation during progression

    DEFF Research Database (Denmark)

    Corsino, P.; Davis, B.; Law, M.;

    2007-01-01

    mediate some of the transforming effects that result from cyclin D1 overexpression in human breast cancers. MMTV-DIK2 cancer cells express the hepatocyte growth factor (HGF) receptor, c-Met. MMTV-D1K2 cancer cells also secrete transforming growth factor beta (TGF beta), but are relatively resistant to TGF......Cyclin D1/cyclin-dependent kinase 2 (Cdk2) complexes are present at high frequency in human breast cancer cell lines, but the significance of this observation is unknown. This report shows that expression of a cyclin D1-Cdk2 fusion protein under the control of the mouse mammary tumor virus (MMITV...... beta antiproliferative effects. Fibroblasts derived from MMTV-DIK2 tumors secrete factors that stimulate the proliferation of MMTV-D1K2 cancer cells, stimulate c-Met tyrosine phosphorylation, and stimulate the phosphorylation of the downstream signaling intermediates p70(s6k) and Akt on activating...

  14. Exhibit Engineering

    DEFF Research Database (Denmark)

    Mortensen, Marianne Foss

    ) a synthesis of the findings from the first two studies with findings from the literature to generate two types of results: a coherent series of suggestions for a design iteration of the studied exhibit as well as a more general normative model for exhibit engineering. Finally, another perspective...

  15. Disagreement in genotyping results of drug resistance alleles of the Plasmodium falciparum dihydrofolate reductase (Pfdhfr) gene by allele-specific PCR (ASPCR) assays and Sanger sequencing.

    Science.gov (United States)

    Sharma, Divya; Lather, Manila; Dykes, Cherry L; Dang, Amita S; Adak, Tridibes; Singh, Om P

    2016-01-01

    The rapid spread of antimalarial drug resistance in Plasmodium falciparum over the past few decades has necessitated intensive monitoring of such resistance for an effective malaria control strategy. P. falciparum dihydropteroate synthase (Pfdhps) and P. falciparum dihydrofolate reductase (Pfdhfr) genes act as molecular markers for resistance against the antimalarial drugs sulphadoxine and pyrimethamine, respectively. Resistance to pyrimethamine which is used as a partner drug in artemisinin combination therapy (ACT) is associated with several mutations in the Pfdhfr gene, namely A16V, N51I, C59R, S108N/T and I164L. Therefore, routine monitoring of Pfdhfr-drug-resistant alleles in a population may help in effective drug resistance management. Allele-specific PCR (ASPCR) is one of the commonly used methods for molecular genotyping of these alleles. In this study, we genotyped 55 samples of P. falciparum for allele discrimination at four codons of Pfdhfr (N51, C59, S108 and I164) by ASPCR using published methods and by Sanger's DNA sequencing method. We found that the ASPCR identified a significantly higher number of mutant alleles as compared to the DNA sequencing method. Such discrepancies arise due to the non-specificity of some of the allele-specific primer sets and due to the lack of sensitivity of Sanger's DNA sequencing method to detect minor alleles present in multiple clone infections. This study reveals the need of a highly specific and sensitive method for genotyping and detecting minor drug-resistant alleles present in multiple clonal infections.

  16. Genetic diversification of methicillin-resistant Staphylococcus aureus as a function of prolonged geographic dissemination and as measured by binary typing and other genotyping methods.

    Science.gov (United States)

    van Leeuwen, W; van Belkum, A; Kreiswirth, B; Verbrugh, H

    1998-01-01

    The aim of the present study was to determine the extent of genome evolution among methicillin-resistant Staghylococcus aureus (MRSA) strains. Three different collections of strains were analysed, comprising locally, nationally and internationally disseminated genotypes. Various genotyping assays displaying different levels of resolution were used. Geographically and temporally diverse MRSA strains comprised the international group. MRSA strains recovered during an outbreak in a New York City hospital and Portuguese MRSA isolates, all resembling the so-called Iberian clone, were included in the local and national collections, respectively. Genotypes were determined by genome scanning typing techniques and procedures which analyse specific DNA elements only. The outbreak strains showed subclonal variation, whereas the Portuguese isolates displayed an increased number of genotypes. Among the epidemiologically unrelated MRSA strains, the different genotyping techniques revealed a wide heterogeneity of types. Different typing techniques appeared to show different levels of resolution, which could be correlated with the extent of geographic spread; the more pronounced the spread, the higher the degree of genome evolution. Binary typing and randomly amplified polymorphic DNA analysis are the typing methods of choice for determining (non)identity among strains that have a recent common ancestor and have undergone yet limited dissemination.

  17. Biofilm-Forming Methicillin-Resistant Staphylococcus aureus Survive in Kupffer Cells and Exhibit High Virulence in Mice

    Directory of Open Access Journals (Sweden)

    Takuto Oyama

    2016-06-01

    Full Text Available Although Staphylococcus aureus is part of the normal body flora, heavy usage of antibiotics has resulted in the emergence of methicillin-resistant strains (MRSA. MRSA can form biofilms and cause indwelling foreign body infections, bacteremia, soft tissue infections, endocarditis, and osteomyelitis. Using an in vitro assay, we screened 173 clinical blood isolates of MRSA and selected 20 high-biofilm formers (H-BF and low-biofilm formers (L-BF. These were intravenously administered to mice and the general condition of mice, the distribution of bacteria, and biofilm in the liver, lung, spleen, and kidney were investigated. MRSA count was the highest in the liver, especially within Kupffer cells, which were positive for acid polysaccharides that are associated with intracellular biofilm. After 24 h, the general condition of the mice worsened significantly in the H-BF group. In the liver, bacterial deposition and aggregation and the biofilm-forming spot number were all significantly greater for H-BF group than for L-BF. CFU analysis revealed that bacteria in the H-BF group survived for long periods in the liver. These results indicate that the biofilm-forming ability of MRSA is a crucial factor for intracellular persistence, which could lead to chronic infections.

  18. Canine Mammary Cancer Stem Cells are Radio- and Chemo- Resistant and Exhibit an Epithelial-Mesenchymal Transition Phenotype.

    Science.gov (United States)

    Pang, Lisa Y; Cervantes-Arias, Alejandro; Else, Rod W; Argyle, David J

    2011-03-30

    Canine mammary carcinoma is the most common cancer among female dogs and is often fatal due to the development of distant metastases. In humans, solid tumors are made up of heterogeneous cell populations, which perform different roles in the tumor economy. A small subset of tumor cells can hold or acquire stem cell characteristics, enabling them to drive tumor growth, recurrence and metastasis. In veterinary medicine, the molecular drivers of canine mammary carcinoma are as yet undefined. Here we report that putative cancer stem cells (CSCs) can be isolated form a canine mammary carcinoma cell line, REM134. We show that these cells have an increased ability to form tumorspheres, a characteristic of stem cells, and that they express embryonic stem cell markers associated with pluripotency. Moreover, canine CSCs are relatively resistant to the cytotoxic effects of common chemotherapeutic drugs and ionizing radiation, indicating that failure of clinical therapy to eradicate canine mammary cancer may be due to the survival of CSCs. The epithelial to mesenchymal transition (EMT) has been associated with cancer invasion, metastasis, and the acquisition of stem cell characteristics. Our results show that canine CSCs predominantly express mesenchymal markers and are more invasive than parental cells, indicating that these cells have a mesenchymal phenotype. Furthermore, we show that canine mammary cancer cells can be induced to undergo EMT by TGFβ and that these cells have an increased ability to form tumorspheres. Our findings indicate that EMT induction can enrich for cells with CSC properties, and provide further insight into canine CSC biology.

  19. Canine Mammary Cancer Stem Cells are Radio- and Chemo-Resistant and Exhibit an Epithelial-Mesenchymal Transition Phenotype

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Lisa Y., E-mail: lisa.pang@ed.ac.uk; Cervantes-Arias, Alejandro; Else, Rod W.; Argyle, David J. [Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Easter Bush, Midlothian, EH25 9RG (United Kingdom)

    2011-03-30

    Canine mammary carcinoma is the most common cancer among female dogs and is often fatal due to the development of distant metastases. In humans, solid tumors are made up of heterogeneous cell populations, which perform different roles in the tumor economy. A small subset of tumor cells can hold or acquire stem cell characteristics, enabling them to drive tumor growth, recurrence and metastasis. In veterinary medicine, the molecular drivers of canine mammary carcinoma are as yet undefined. Here we report that putative cancer stem cells (CSCs) can be isolated form a canine mammary carcinoma cell line, REM134. We show that these cells have an increased ability to form tumorspheres, a characteristic of stem cells, and that they express embryonic stem cell markers associated with pluripotency. Moreover, canine CSCs are relatively resistant to the cytotoxic effects of common chemotherapeutic drugs and ionizing radiation, indicating that failure of clinical therapy to eradicate canine mammary cancer may be due to the survival of CSCs. The epithelial to mesenchymal transition (EMT) has been associated with cancer invasion, metastasis, and the acquisition of stem cell characteristics. Our results show that canine CSCs predominantly express mesenchymal markers and are more invasive than parental cells, indicating that these cells have a mesenchymal phenotype. Furthermore, we show that canine mammary cancer cells can be induced to undergo EMT by TGFβ and that these cells have an increased ability to form tumorspheres. Our findings indicate that EMT induction can enrich for cells with CSC properties, and provide further insight into canine CSC biology.

  20. Transgenic tomato plants overexpressing tyramine N-hydroxycinnamoyltransferase exhibit elevated hydroxycinnamic acid amide levels and enhanced resistance to Pseudomonas syringae.

    Science.gov (United States)

    Campos, Laura; Lisón, Purificación; López-Gresa, María Pilar; Rodrigo, Ismael; Zacarés, Laura; Conejero, Vicente; Bellés, José María

    2014-10-01

    Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.

  1. Healthy sheep that differ in scrapie associated PRNP genotypes exhibit significant differences of expression pattern associated with immune response and cell-to-cell signalling in retropharyngeal lymph nodes.

    Science.gov (United States)

    Komolka, Katrin; Ponsuksili, Siriluck; Schwerin, Manfred

    2013-04-15

    The present study was conducted to test the hypothesis whether prion protein gene (PRNP) associated scrapie susceptibility is connected with physiological changes in tissue involved in pathogen uptake, migration and propagation. Jejunum, ileal Peyer's patches, retropharyngeal lymph nodes, brain stem and liver of healthy and non scrapie-infected sheep with PRNP genotypes representing the scrapie risk class R1 (scrapie-resistant) and R5 (scrapie-susceptible), respectively, were comparatively analysed by microarray technology and quantitative reverse transcriptase polymerase chain reaction (RT qPCR). Significantly higher expression levels of genes involved in immune response and cell communication pathways in retropharyngeal lymph nodes of R1 sheep in comparison with R5 animals strongly suggest PRNP associated physiological processes with impact as an early barrier in pathogen defence. Equal expression patterns in brain stem suggest no physiological differences in brain of healthy R1 and R5 animals. In addition, similar expression pattern in liver indicates that there are no transcriptional differences in genes of the hepatic energy metabolism between animals of scrapie classes R1 and R5.

  2. Malignant T cells exhibit CD45 resistant Stat 3 activation and proliferation in cutaneous T cell lymphoma

    DEFF Research Database (Denmark)

    Krejsgaard, T; Helvad, Rikke; Ralfkiær, Elisabeth

    2010-01-01

    CD45 is a protein tyrosine phosphatase, which is well-known for regulating antigen receptor signalling in T and B cells via its effect on Src kinases. It has recently been shown that CD45 can also dephosphorylate Janus kinases (Jaks) and thereby regulate Signal transducer and activator of transcr......CD45 is a protein tyrosine phosphatase, which is well-known for regulating antigen receptor signalling in T and B cells via its effect on Src kinases. It has recently been shown that CD45 can also dephosphorylate Janus kinases (Jaks) and thereby regulate Signal transducer and activator...... of transcription (Stat) activation and cytokine-induced proliferation in lymphocytes. Consequently, CD45 dysregulation could be implicated in aberrant Jak/Stat activation and proliferation in lymphoproliferative diseases. Despite high expression of the CD45 ligand, Galectin-1, in skin lesions from cutaneous T......-cell lymphoma (CTCL), the malignant T cells exhibit constitutive activation of the Jak3/Stat3 signalling pathway and uncontrolled proliferation. We show that CD45 expression is down-regulated on malignant T cells when compared to non-malignant T cells established from CTCL skin lesions. Moreover, CD45 cross...

  3. Canine Mammary Cancer Stem Cells are Radio- and Chemo- Resistant and Exhibit an Epithelial-Mesenchymal Transition Phenotype

    Directory of Open Access Journals (Sweden)

    David J. Argyle

    2011-03-01

    Full Text Available Canine mammary carcinoma is the most common cancer among female dogs and is often fatal due to the development of distant metastases. In humans, solid tumors are made up of heterogeneous cell populations, which perform different roles in the tumor economy. A small subset of tumor cells can hold or acquire stem cell characteristics, enabling them to drive tumor growth, recurrence and metastasis. In veterinary medicine, the molecular drivers of canine mammary carcinoma are as yet undefined. Here we report that putative cancer stem cells (CSCs can be isolated form a canine mammary carcinoma cell line, REM134. We show that these cells have an increased ability to form tumorspheres, a characteristic of stem cells, and that they express embryonic stem cell markers associated with pluripotency. Moreover, canine CSCs are relatively resistant to the cytotoxic effects of common chemotherapeutic drugs and ionizing radiation, indicating that failure of clinical therapy to eradicate canine mammary cancer may be due to the survival of CSCs. The epithelial to mesenchymal transition (EMT has been associated with cancer invasion, metastasis, and the acquisition of stem cell characteristics. Our results show that canine CSCs predominantly express mesenchymal markers and are more invasive than parental cells, indicating that these cells have a mesenchymal phenotype. Furthermore, we show that canine mammary cancer cells can be induced to undergo EMT by TGFβ and that these cells have an increased ability to form tumorspheres. Our findings indicate that EMT induction can enrich for cells with CSC properties, and provide further insight into canine CSC biology.

  4. Human Exhibitions

    DEFF Research Database (Denmark)

    Andreassen, Rikke

    From 1870s to 1910s, more than 50 exhibitions of so-called exotic people took place in Denmark. Here large numbers of people of Asian and African origin were exhibited for the entertainment and ‘education’ of a mass audience. Several of these exhibitions took place in Copenhagen Zoo. Here different...... light on the staging of exhibitions, the daily life of the exhibitees, the wider connections between shows across Europe and the thinking of the time on matters of race, science, gender and sexuality. A window onto contemporary racial understandings, the book presents interviews with the descendants...... of displayed people, connecting the attitudes and science of the past with both our (continued) modern fascination with ‘the exotic’, and contemporary language and popular culture. As such, it will be of interest to scholars of sociology, anthropology and history working in the areas of gender and sexuality...

  5. Brief communication: detection of clinical Klebsiella pneumoniae isolates from China containing transferable quinolone resistance determinants exhibiting resistance to both aminoglycoside and β-lactams.

    Science.gov (United States)

    Xue, Xinying; Pan, Lei; Zhang, Naxin; Liu, Yuxia; Luo, Yanping; Zhou, Guang; Guan, Xizhou

    2014-01-01

    Though aminoglycosides are routinely used clinically as antimicrobial agents for the treatment of severe infections due to Klebsiella pneumoniae, resistance to the same is an increasing problem. One such resistance mechanism is the production of 16S rRNA methylases. The objective of the current study was to investigate the prevalence and molecular epidemology of 16S rRNA methylase genes among 43 K. pneumoniae isolates (each of which had at least one PQMR gene and ciprofloxacin minimum inhibitory concentration greater than 0.25) recovered from nine tertiary hospitals in China. Our results suggest great genetic variation in terms of 16S rRNA methylase gene of K. pneumoniae hosts containing at least one PQMR gene. This further reinforces the clinical and systemic urgency required to characterize and block their transmission routes.

  6. Fluctuations in peroxidase and catalase activities of resistant and susceptible black gram (Vigna mungo (L.) Hepper) genotypes elicited by Bemisia tabaci (Gennadius) feeding.

    Science.gov (United States)

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Sandhu, Jeet Singh

    2012-10-01

    Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae), is a serious pest of black gram, (Vigna mungo (L.) Hepper), an important legume pulse crop grown in north India. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to whitefly in nine black gram genotypes. Oxidative enzyme activity was estimated spectrophotometrically from leaf samples collected at 30 and 50 d after sowing (DAS) from whitefly infested and uninfested plants. The enzymes showed different activity levels at different times after the infestation. The results indicated that in general, whitefly infestation increased the activities of peroxidase and decreased the catalase activity. Resistant genotypes NDU 5-7 and KU 99-20 recorded higher peroxidase and catalase activities at 30 and 50 DAS under whitefly-stress conditions as compared with non-stressed plants. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of black gram plants against B. tabaci infestation. The potential mechanisms to explain the correlation of resistance to whitefly in black gram genotypes with higher activities of oxidative enzymes are also discussed.

  7. T3SS-dependent differential modulations of the jasmonic acid pathway in susceptible and resistant genotypes of Malus spp. challenged with Erwinia amylovora.

    Science.gov (United States)

    Dugé De Bernonville, Thomas; Gaucher, Matthieu; Flors, Victor; Gaillard, Sylvain; Paulin, Jean-Pierre; Dat, James F; Brisset, Marie-Noëlle

    2012-06-01

    Fire blight is a bacterial disease of Maloideae caused by Erwinia amylovora (Ea). This necrogenic enterobacterium uses a type III secretion system (T3SS) to inject type III effectors into the plant cells to cause disease on its susceptible hosts, including economically important crops like apple and pear. The expressions of marker genes of the salicylic acid (SA) and jasmonic acid (JA) defense regulation pathways were monitored by RT-qPCR in leaves of two apple genotypes, one susceptible and one resistant, challenged with a wild type strain, a T3SS-deficient strain or water. The transcriptional data taken together with hormone level measurements indicated that the SA pathway was similarly induced in both apple genotypes during infection by Ea. On the contrary, the data clearly showed a strong T3SS-dependent down-regulation of the JA pathway in leaves of the susceptible genotype but not in those of the resistant one. Accordingly, methyl-jasmonate treated susceptible plants displayed an increased resistance to Ea. Bacterial mutant analysis indicated that JA manipulation by Ea mainly relies on the type III effector DspA/E. Taken together, our data suggest that the T3SS-dependent down-regulation of the JA pathway is a critical step in the infection process of Malus spp. by Ea.

  8. Treponema pallidum pallidum Genotypes and Macrolide Resistance Status in Syphilitic Lesions among Patients at 2 Sexually Transmitted Infection Clinics in Lima, Peru.

    Science.gov (United States)

    Flores, Juan Antonio; Vargas, Silver Keith; Leon, Segundo Ramos; Perez, Danny Giancarlo; Ramos, Lourdes Beatriz; Chow, Jeremy; Konda, Kelika Anne; Calvo, Gino Mauricio; Salvatierra, Hector J; Klaussner, Jeffrey D; Caceres, Carlos Fernando

    2016-07-01

    We report the circulating genotypes and the frequency of macrolide-resistance patterns among Treponema pallidum pallidum DNA isolated from syphilitic lesions from patients who attended 2 sexual health clinics in Lima, Peru. We implemented and used a molecular typing scheme to describe local T. pallidum pallidum strains. Among 14 specimens, subtype 14d/f was the most prevalent strain in 7 fully typed T. pallidum DNA specimens obtained from men who have sex with men and transgender women presenting with chancre-like lesions. No macrolide-resistance mutations were found in T. pallidum DNA from 10 lesions.

  9. Early detection of multi-drug resistance and common mutations in Mycobacterium tuberculosis isolates from Delhi using GenoType MTBDRplus assay

    OpenAIRE

    2015-01-01

    Purpose: There is scarcity of prevalence data of multi-drug-resistant tuberculosis (MDR-TB) data and common mutations responsible in North India. This study aimed to detect MDR-TB among MDR-TB suspects from Delhi and mutation patterns using GenoType MTBDRplus assay. Materials and Methods: All MDR suspects in five districts of New Delhi were referred to the laboratory from 1 st October 2011 to 31 st December 2012 as per criterion defined by Programmatic Management of Drug Resistant Tuberculosi...

  10. The Genotype MTBDRplus ver. 2.0 test as a quick indicator of resistance to rifampicin and isoniazid in Mycobacterium tuberculosis strains

    Directory of Open Access Journals (Sweden)

    Salvatore Nisticò

    2013-08-01

    Full Text Available Tuberculosis is still a global emergency and a major public health problem, in some cases related to the appearance of strains of multi drug resistance (MDR and extensive drug resistance (XDR Mycobacterium tuberculosis complex.The correct determination of antibiotic sensitivity profiles is therefore crucial to carry out appropriate treatment aimed to decrease the infectivity of each patient and to reduce mortality. The poor adherence to treatment by the patient or the use of therapies based on a single drug, as a result of incorrect requirements, promote the development of drug-resistance. Have some time on the market of molecular diagnostic tests that allow, quickly and directly from biological sample to search for resistance genes some key drugs of anti-TB therapy (Rifampicin and Isoniazid. One of the tests in question is the Genotype MTBDRplus ver 2.0 which can reveal the presence of genes for resistance to Isoniazid (INH and Rifampin (RMP.The loci analyzed are those corresponding to the rpoB gene for rifampicin, katG and inhA for isoniazid. Our study is based on the analysis of 83 strains of tubercular Mycobacteria identified and isolated from patients with tuberculosis disease and subjected to the tests sensitivity, searching for mutations and phenotypic susceptibility testing for Rifampicin and Isoniazid.The comparison of the results has shown that the results obtained using the Genotype MTBDRplus ver 2.0 test, were similar to the results obtained by the traditional susceptibility testing.

  11. Biological Characteristics of Experimental Genotype Mixtures of Cydia Pomonella Granulovirus (CpGV): Ability to Control Susceptible and Resistant Pest Populations.

    Science.gov (United States)

    Graillot, Benoit; Bayle, Sandrine; Blachere-Lopez, Christine; Besse, Samantha; Siegwart, Myriam; Lopez-Ferber, Miguel

    2016-05-21

    The detection of resistance in codling moth (Cydia pomonella) populations against the Mexican isolate of its granulovirus (CpGV-M), raised questions on the sustainability of the use of this biological insecticide. In resistant host cells, CpGV-M is not able to complete its replication cycle because replication is blocked at an early step. Virus isolates able to overcome this resistance have been characterized-among them, the CpGV-R5 isolate. In mixed infections on resistant insects, both CpGV-M and CpGV-R5 viruses replicate, while CpGV-M alone does not induce mortality. Genetically heterogeneous virus populations, containing 50% of each CpGV-M and CpGV-R5 appear to control resistant host populations as well as CpGV-R5 alone at the same final concentration, even if the concentration of CpGV-R5 is only half in the former. The use of mixed genotype virus preparations instead of genotypically homogeneous populations may constitute a better approach than traditional methods for the development of baculovirus-based biological insecticides.

  12. Preliminary Trial of 11 New Hybrid Maize Genotype to The Resistance on Java Downy Mildew (Peronosclerospora maydis

    Directory of Open Access Journals (Sweden)

    Budi Setyawan

    2016-04-01

    Full Text Available Maize or corn (Zea mays L. belongs to the family of grasses (Poaceae.  Maize is grown globally and one of the most important cereal crop in the world.  In many countries, corn is the main agricultural crop, and are used as food, feed and industrial raw materials. Together with rice and wheat, corn included in the cereals that provide about 65% carbohydrates and 50% protein that humans need. For this purpose, many developing countries, especially in Asia and Africa are in a strong effort to increase their corn yields through the use of better seeds.  Although in Indonesia, corn is the second important food crop after rice, however, with the rapid growth of the livestock industry, corn is a major component (60% in feed ingredient.  It is estimated that more than 55% of the corn used for feed in Indonesia.  Java Downy Mildew (Peronosclerospora maydis is the main disease that is concerned by maize corn growers. This disease often resulting in substantial losses for farmers, even reach 100% in susceptible genotypes.  Therefore trial on 11 new prospective hybrids was conducted with the expectation that they can be classified in the criteria “less resistant or higher” according to the criteria of modified Reid (2005.  Of the 11 new hybrids, 3 new hybrids (27.3% classified in the criteria “very resistant”, 4 new hybrids (36.4% classified in the criteria “resistant”, 2 new hybrid (18.2% classified in the criteria “less resistant”, and 2 other new hybrids (18.2% classified in the criteria “less susceptible”.

  13. Genotyping-by-Sequencing Uncovers the Introgression Alien Segments Associated with Sclerotinia Basal Stalk Rot Resistance from Wild Species-I. Helianthus argophyllus and H. petiolaris.

    Science.gov (United States)

    Qi, Lili; Long, Yunming; Talukder, Zahirul I; Seiler, Gerald J; Block, Charles C; Gulya, Thomas J

    2016-01-01

    Basal stalk rot (BSR), caused by Sclerotinia sclerotiorum, is a devastating disease in sunflower worldwide. The progress of breeding for Sclerotinia BSR resistance has been hampered due to the lack of effective sources of resistance for cultivated sunflower. Our objective was to transfer BSR resistance from wild annual Helianthus species into cultivated sunflower and identify the introgressed alien segments associated with BSR resistance using a genotyping-by-sequencing (GBS) approach. The initial crosses were made between the nuclear male sterile HA 89 with the BSR resistant plants selected from wild Helianthus argophyllus and H. petiolaris populations in 2009. The selected resistant F1 plants were backcrossed to HA 458 and HA 89, respectively. Early generation evaluations of BSR resistance were conducted in the greenhouse, while the BC2F3 and subsequent generations were evaluated in the inoculated field nurseries. Eight introgression lines; six from H. argophyllus (H.arg 1 to H.arg 6), and two from H. petiolaris (H.pet 1 and H.pet 2), were selected. These lines consistently showed high levels of BSR resistance across seven environments from 2012 to 2015 in North Dakota and Minnesota, USA. The mean BSR disease incidence (DI) for H.arg 1 to H.arg 6, H.pet 1, and H.pet 2 was 3.0, 3.2, 0.8, 7.2, 7.7, 1.9, 2.5, and 4.4%, compared to a mean DI of 36.1% for Cargill 270 (susceptible hybrid), 31.0% for HA 89 (recurrent parent), 19.5% for HA 441 (resistant inbred), and 11.6% for Croplan 305 (resistant hybrid). Genotyping of the highly BSR resistant introgression lines using GBS revealed the presence of the H. argophyllus segments in linkage groups (LGs) 3, 8, 9, 10, and 11 of the sunflower genome, and the H. petiolaris segments only in LG8. The shared polymorphic SNP loci in the introgression lines were detected in LGs 8, 9, 10, and 11, indicating the common introgression regions potentially associated with BSR resistance. Additionally, a downy mildew resistance gene, Pl17

  14. Distribution of natural resistance to NS3 protease inhibitors in hepatitis C genotype 1a separated into clades 1 and 2 and in genotype 1b of HIV-infected patients.

    Science.gov (United States)

    Bagaglio, S; Uberti-Foppa, C; Messina, E; Merli, M; Hasson, H; Andolina, A; Galli, A; Lazzarin, A; Morsica, G

    2016-04-01

    Naturally occurring resistance-associated variants (RAVs) within the protease domain of hepatitis C virus (HCV) genotype (G) 1a separated into clades 1 and 2, and G1b were investigated in 59 HIV/HCV coinfected patients. RAVs were detected in 10/23 G1a/clade 1 and 1/19 G1b (p 0.0059). A similar frequency of RAVs was found when comparing G1a/clade 2 and G1b (p 0.1672). A cross-resistance to the macrocyclic compounds simeprevir and paritaprevir was detected in two G1a/clade 2 and 1 G1b sequences and none of G1a/clade 1 sequences. The simultaneous characterization of subtype and natural RAVs by population analysis of the NS3 domain by may add important information for anti-HCV treatment strategies including protease inhibitors.

  15. Prueba molecular Genotype® MTBDRplus, una alternativa para la detección rápida de tuberculosis multidrogorresistente Molecular test Genotype® MTBDRplus, an alternative to rapid detection of multidrug resistance tuberculosis

    Directory of Open Access Journals (Sweden)

    Luis Asencios

    2012-03-01

    Full Text Available La prueba molecular Genotype®MTBDRplus, es un método que permite identificar las mutaciones más frecuentes asociadas con la resistencia a las drogas antituberculosas de primera línea: isoniacida (INH y rifampicina (RIF. El objetivo de este estudio fue evaluar el desempeño de la prueba molecular con cultivos y muestras de esputo con baciloscopía positiva. Se evaluó 95 cultivos y 100 esputos con perfiles de resistencia previamente determinados por el método de referencia "proporciones agar en placa" (APP. La prueba molecular a partir de cultivos mostró una sensibilidad de 100%; 97,5% y 96,9% para RIF, INH y multidrogorresistente (MDR respectivamente; mientras que para esputo la sensibilidad fue de 95,7%; 96,8% y 95,2% para RIF, INH y MDR respectivamente. Se concluye que Genotype®MTBDRplus es una herramienta muy útil para la detección rápida de la resistencia a INH y RIF simultáneamente (MDR en un máximo de 72 h a partir de esputo o de cultivo.The Genotype®MTBDRplus molecular test is a method that allows identification of the most frequent mutations associated with resistance to major first-line antituberculosis drugs, Isoniazid (INH and Rifampicin (RFP. The aim of this study was to evaluate the performance of the molecular test with culture and smear- positive sputum samples. We evaluated 95 cultures and 100 sputum samples with resistance profiles previously determined by the reference method "Agar Plate Proportions" (APP. The molecular test from cultures showed a sensitivity of 100 %, 97,5 % and 96,97 % for RIF, INH and MDR respectively while from sputums the sensitivity was 95,65 %, 96,77 % and 95,24 % for RIF, INH and MDR respectively. We conclude that the molecular test Genotype®MTBDRplus is a very useful tool to detect resistance to isoniazid and rifampicin simultaneously (MDR-TB in up to 72 hours from sputum samples or cultures.

  16. Early detection of multi-drug resistance and common mutations in Mycobacterium tuberculosis isolates from Delhi using GenoType MTBDRplus assay

    Directory of Open Access Journals (Sweden)

    R Singhal

    2015-01-01

    Full Text Available Purpose: There is scarcity of prevalence data of multi-drug-resistant tuberculosis (MDR-TB data and common mutations responsible in North India. This study aimed to detect MDR-TB among MDR-TB suspects from Delhi and mutation patterns using GenoType MTBDRplus assay. Materials and Methods: All MDR suspects in five districts of New Delhi were referred to the laboratory from 1 st October 2011 to 31 st December 2012 as per criterion defined by Programmatic Management of Drug Resistant Tuberculosis (PMDT. GenoType MTBDRplus assay was performed on 2182 samples or cultures and mutations in the rpoB gene for rifampicin (RIF and katG and inhA genes for isoniazid (INH were analyzed. Results: A total of 366 (16.8% MDR-TB cases were diagnosed. MDR rate was found to be 32%, 16.6% and 10.2% during criterion A, B and C respectively. The most common mutation detected for RIF was S531L (59.0% and for INH was S315T1 (88.3%. Mutations S531L and S315T1 occurred significantly higher in MDR strains as compared to RIF mono-resistant and INH mono-resistant strains, respectively. Average laboratory turn-around time (TAT for dispatch of result to districts for test conducted on samples was 4.4 days. Conclusion: GenoType MTBDRplus is a useful assay for rapid detection of MDR-TB. The common mutations for RIF and INH were similar to those seen in other regions. However, mutations determining MDR strains and mono-resistant strains differed significantly for both RIF and INH.

  17. Mating Success, Longevity, and Fertility of Diabrotica virgifera virgifera LeConte (Chrysomelidae: Coleoptera in Relation to Body Size and Cry3Bb1-Resistant and Cry3Bb1-Susceptible Genotypes

    Directory of Open Access Journals (Sweden)

    Bryan Wade French

    2015-11-01

    Full Text Available Insect resistance to population control methodologies is a widespread problem. The development of effective resistance management programs is often dependent on detailed knowledge regarding the biology of individual species and changes in that biology associated with resistance evolution. This study examined the reproductive behavior and biology of western corn rootworm beetles of known body size from lines resistant and susceptible to the Cry3Bb1 protein toxin expressed in transgenic Bacillus thuringiensis maize. In crosses between, and within, the resistant and susceptible genotypes, no differences occurred in mating frequency, copulation duration, courtship duration, or fertility; however, females mated with resistant males showed reduced longevity. Body size did not vary with genotype. Larger males and females were not more likely to mate than smaller males and females, but larger females laid more eggs. Moderately strong, positive correlation occurred between the body sizes of successfully mated males and females; however, weak correlation also existed for pairs that did not mate. Our study provided only limited evidence for fitness costs associated with the Cry3Bb1-resistant genotype that might reduce the persistence in populations of the resistant genotype but provided additional evidence for size-based, assortative mating, which could favor the persistence of resistant genotypes affecting body size.

  18. Young overweight and obese women with lower circulating osteocalcin concentrations exhibit higher insulin resistance and concentrations of C-reactive protein.

    Science.gov (United States)

    Lucey, Alice J; Paschos, Georgios K; Thorsdottir, Inga; Martínéz, J Alfredo; Cashman, Kevin D; Kiely, Máireád

    2013-01-01

    The role of the skeleton in the regulation of energy metabolism in humans is not clear. This study investigates the hypothesis that biomarkers of bone turnover are associated with indices of glucose homeostasis and systemic inflammation in young adults. A cross-sectional study investigating the relationships between biomarkers of bone turnover (serum total and uncarboxylated osteocalcin, bone-specific alkaline phosphatase, C-telopeptide of type I collagen, urinary N-telopeptide of type I collagen) and glucose metabolism (fasting plasma glucose [FPG], insulin, insulin resistance [homeostatic model assessment of insulin resistance]), systemic inflammation (high-sensitivity C-reactive protein [hsCRP] and interleukin-6), adipokines (leptin and adiponectin), and body composition was conducted in 268 young, nondiabetic overweight and obese adults aged 20 to 40 years (116 men, 152 women; body mass index, 27.5-32.5 kg/m(2)). Data on diet, physical activity, serum 25-hydroxyvitamin D, and parathyroid hormone were also collected. In women, there was a stepwise increase in lean body mass (P insulin resistance (β = -0.508; P = .001; 95% CI, -10.93 to -3.17) in women with total osteocalcin concentrations below the group median. Men in the lowest tertile of uncarboxylated osteocalcin had twice the concentration of hsCRP than did other men (P = .05). In this sample, women with less lean body mass had lower circulating total osteocalcin concentrations and exhibited higher FPG, insulin resistance, and hsCRP compared with their similarly sized counterparts, suggesting that associations between osteocalcin and systemic inflammation, glucose homeostasis, and insulin resistance may be influenced by differences in sex and body composition.

  19. High-resolution mapping of resistance to cassava mosaic geminiviruses in cassava using genotyping-by-sequencing and its implications for breeding.

    Science.gov (United States)

    Rabbi, Ismail Y; Hamblin, Martha T; Kumar, P Lava; Gedil, Melaku A; Ikpan, Andrew S; Jannink, Jean-Luc; Kulakow, Peter A

    2014-06-24

    Cassava mosaic disease (CMD), caused by different species of cassava mosaic geminiviruses (CMGs), is the most important disease of cassava in Africa and the Indian sub-continent. The cultivated cassava species is protected from CMD by polygenic resistance introgressed from the wild species Manihot glaziovii and a dominant monogenic type of resistance, named CMD2, discovered in African landraces. The ability of the monogenic resistance to confer high levels of resistance in different genetic backgrounds has led recently to its extensive usage in breeding across Africa as well as pre-emptive breeding in Latin America. However, most of the landraces carrying the monogenic resistance are morphologically very similar and come from a geographically restricted area of West Africa, raising the possibility that the diversity of the single-gene resistance could be very limited, or even located at a single locus. Several mapping studies, employing bulk segregant analysis, in different genetic backgrounds have reported additional molecular markers linked to supposedly new resistance genes. However, it is not possible to tell if these are indeed new genes in the absence adequate genetic map framework or allelism tests. To address this important question, a high-density single nucleotide polymorphism (SNP) map of cassava was developed through genotyping-by-sequencing a bi-parental mapping population (N=180) that segregates for the dominant monogenic resistance to CMD. Virus screening using PCR showed that CMD symptoms and presence of virus were strongly correlated (r=0.98). Genome-wide scan and high-resolution composite interval mapping using 6756 SNPs uncovered a single locus with large effect (R(2)=0.74). Projection of the previously published resistance-linked microsatellite markers showed that they co-occurred in the same chromosomal location surrounding the presently mapped resistance locus. Moreover, their relative distance to the mapped resistance locus correlated with

  20. Salmonella Typhimurium exhibits fluoroquinolone resistance mediated by the accumulation of the antioxidant molecule H2S in a CysK-dependent manner.

    Science.gov (United States)

    Frávega, J; Álvarez, R; Díaz, F; Inostroza, O; Tejías, C; Rodas, P I; Paredes-Sabja, D; Fuentes, J A; Calderón, I L; Gil, F

    2016-12-01

    To evaluate the contribution of cysK and cysM to the fluoroquinolone (ofloxacin) antibiotic resistance in Salmonella Typhimurium, and their impact on H2S and cysteine production through targeted mutagenesis. Salmonella Typhimurium 14028s and its cysK and cysM mutants were tested for their susceptibility to ofloxacin, as determined by a broth microdilution test (to determine the MIC) and survival curves. H2S levels were measured by the Pb(AC)2 method and cysteine levels were determined using 5,5-dithio-bis-2-nitrobenzoic acid. DNA damage induced by antibiotic treatment was determined by PFGE. Finally, expression of cysK and cysM genes under antibiotic treatment was determined by real-time reverse transcription PCR. As determined by MIC, the ΔcysK strain was more resistant to ofloxacin, a reactive oxygen species (ROS)-producing fluoroquinolone, than the WT and ΔcysM strains, which correlates with survival curves. Moreover, the ΔcysK strain exhibited higher H2S levels and lower cysteine levels than the WT strain. Finally, the ΔcysK strain exhibited lower DNA damage upon challenge with ofloxacin than the WT and ΔcysM strains. These results are in accordance with lower expression of cysK under ofloxacin treatment in the WT strain. This work demonstrated that cysteine metabolism in Salmonella Typhimurium modulated H2S levels, conferring resistance to second-generation fluoroquinolones. © The Author 2016. 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.

  1. Epidemiology, Antimicrobial Resistance and β-lactamase Genotypic Features of Enteropathogenic Escherichia coli Isolated from Children with Diarrhea in Southern China.

    Science.gov (United States)

    Huang, Yong; Shan, Xue-feng; Deng, Haijun; Huang, Yu-jun; Mu, Xiao-ping; Huang, Ai-long; Long, Quan-xin

    2015-01-01

    The main objective of this study was to investigate the epidemiology, drug resistance and β-lactamase genotype distribution of enteropathogenic Escherichia coli (EPEC) isolated from pediatric patients with diarrhea in southern China. The prevalence of EPEC in children with diarrhea was 3.53%. The commonest serotypes were O55:K59 and O126:K71, and the typical EPEC were more prevalent than atypical EPEC (51 vs 7). Isolates from this region were most commonly found to be resistant to ampicillin and cotrimoxazole, followed by chloramphenicol, ceftriaxone, and ceftazidime. More than 96% of the strains were susceptible to cefoperazone/sulbactam and imipenem. The most common β-lactamase genotypes identified in 58 strains were blaCTX-M-1 (60.3%), blaTEM (56.9%), blaCTX-M-9 (27.6%), and blaSHV (15.5%). Among 58 isolates, 22 strains were found to harbor one β-lactamase gene, and the proportions of resistance to ampicillin, cotrimoxazole, chloramphenicol, ceftriaxone, and ceftazidime, were 81.8%, 63.6%, 40.9%, 18.2%, and 9.1%, respectively. A further 30 strains carrying multiple β-lactamase genes had increased resistance to the above antimicrobial agents (100%, 83.3%, 70.0%, 60.0%, and 30.0%, respectively). In contrast, antibiotic resistance in the last 6 strains without a detectable β-lactamase gene was substantially reduced. Drug resistance may be associated with the β-lactamase gene number, with a greater the number of β-lactamase genes resulting in higher antibiotic resistance.

  2. Phenotypic and genotypic properties of Neisseria gonorrhoeae isolates in Norway in 2009: antimicrobial resistance warrants an immediate change in national management guidelines.

    Science.gov (United States)

    Hjelmevoll, S O; Golparian, D; Dedi, L; Skutlaberg, D H; Haarr, E; Christensen, A; Jørgensen, S; Nilsen, Ø J; Unemo, M; Skogen, V

    2012-06-01

    Despite rapidly diminishing treatment options for Neisseria gonorrhoeae and high levels of ciprofloxacin resistance worldwide, Norwegian guidelines still recommend ciprofloxacin as empirical treatment for gonorrhea. The present study aimed to characterize phenotypical and genotypical properties of N. gonorrhoeae isolates in Norway in 2009. All viable N. gonorrhoeae isolates (n = 114) from six university hospitals in Norway (2009) were collected, representing 42% of all notified gonorrhea cases. Epidemiological data were collected from the Norwegian Surveillance System for Communicable Diseases and linked to phenotypical and genotypical characteristics for each N. gonorrhoeae isolate. Resistance levels to the antimicrobials examined were: ciprofloxacin 78%, azithromycin 11%, cefixime 3.5%, ceftriaxone 1.8%, and spectinomycin 0%. The minimum inhibitory concentrations of gentamicin varied from 1.5 to 8 mg/L. Forty-one (36%) of the isolates were β-lactamase-producing, 17 displayed penA mosaic alleles, and 72 different N. gonorrhoeae multiantigen sequence types (ST; 37 novel) were identified. The most common ST was ST1407 (n = 11), containing penA mosaic allele. Four of these isolates displayed intermediate susceptibility/resistance to cefixime. The N. gonorrhoeae strains circulating in Norway were highly diverse. The level of ciprofloxacin resistance was high and the Norwegian management guidelines should promptly exclude ciprofloxacin as an empirical treatment option for gonorrhea.

  3. Replacement of Porcine CD163 Scavenger Receptor Cysteine-Rich Domain 5 with a CD163-Like Homolog Confers Resistance of Pigs to Genotype 1 but Not Genotype 2 Porcine Reproductive and Respiratory Syndrome Virus.

    Science.gov (United States)

    Wells, Kevin D; Bardot, Rachel; Whitworth, Kristin M; Trible, Benjamin R; Fang, Ying; Mileham, Alan; Kerrigan, Maureen A; Samuel, Melissa S; Prather, Randall S; Rowland, Raymond R R

    2017-01-15

    CD163 knockout (KO) pigs are resistant to infection with genotype 2 (type 2) porcine reproductive and respiratory syndrome virus (PRRSV). Furthermore, the substitution of CD163 scavenger receptor cysteine-rich (SRCR) domain 5 with a homolog of human CD163-like (hCD163L1) SRCR 8 domain confers resistance of transfected HEK cells to type 1 PRRSV. As a means to understand the role of domain 5 in PRRSV infection with both type 1 and type 2 viruses, pigs were genetically modified (GM) to possess one of the following genotypes: complete knockout (KO) of CD163, deletions within SRCR domain 5, or replacement (domain swap) of SRCR domain 5 with a synthesized exon encoding a homolog of hCD163L1 SRCR domain 8. Immunophenotyping of porcine alveolar macrophages (PAMs) showed that pigs with the KO or SRCR domain 5 deletion did not express CD163. When placed in culture, PAMs from pigs with the CD163 KO phenotype were completely resistant to a panel consisting of six type 1 and nine type 2 isolates. PAMs from pigs that possessed the hCD163L1 domain 8 homolog expressed CD163 and supported the replication of all type 2 isolates, but no type 1 viruses. Infection of CD163-modified pigs with representative type 1 and type 2 viruses confirmed the in vitro results. The results confirm that CD163 is the likely receptor for all PRRS viruses. Even though type 1 and type 2 viruses are considered phenotypically similar at several levels, there is a distinct difference between the viral genotypes in the recognition of CD163. Genetic modification of the CD163 gene creates the opportunity to develop production animals that are resistant to PRRS, the costliest viral disease to ever face the swine industry. The results create further opportunities to develop refinements in the modification of CD163 with the goal of making pigs refractory to infection while retaining important CD163 functions. Copyright © 2017 American Society for Microbiology.

  4. Exhibit Engineering

    DEFF Research Database (Denmark)

    Mortensen, Marianne Foss

    of tools and processes to guide the design of educational science exhibits. The guiding paradigm for this development is design-based research, which is characterised by an iterative cycle of design, enactment, and analysis. In the design phase, an educational intervention is planned and carried out based...... on a hypothesised learning process and the means of supporting it. In the enactment phase, the educational intervention is implemented (i.e. the planned lesson is taught, or the museum exhibit is opened to the public). Finally, the analysis phase establishes causality between emergent characteristics...... of the learning outcomes and the design characteristics of the intervention. The analysis process can yield two types of outcomes: Suggestions for the refinement of the specific design in question, and “humble” theory, which is theory that can guide the design of a category of educational interventions...

  5. HOMA, BMI, and Serum Leptin Levels Variations during Antiviral Treatment Suggest Virus-Related Insulin Resistance in Noncirrhotic, Nonobese, and Nondiabetic Chronic Hepatitis C Genotype 1 Patients

    Directory of Open Access Journals (Sweden)

    Alessandro Grasso

    2015-01-01

    Full Text Available Objective. To investigate the relationship between insulin resistance and viral load decay in nondiabetic and noncirrhotic genotype 1 chronic HCV patients during peginterferon and ribavirin treatment and the possible influence of BMI and leptin as metabolic confounders. Methods. 75 consecutive noncirrhotic, nonobese, and nondiabetic patients with genotype 1 chronic hepatitis C treated with peginterferon alpha 2a plus ribavirin were evaluated. HOMA-IR, serum leptin, and BMI were measured in all patients at baseline and at weeks 12 and 48, whereas viral load was measured at the same time points and then 24 weeks after the end of treatment. Results. HOMA-IR was significantly associated with both BMI and leptin at baseline. During peginterferon plus ribavirin treatment, there was a significant reduction of HOMA-IR at weeks 12 and 48 from baseline (P=0.033 and 0.048, resp. in patients who achieved an early viral load decay (EVR, a trend not observed in patients who not achieved EVR. No variations during treatment were observed regarding BMI and leptin irrespective of EVR. Conclusion. The early reduction of HOMA-IR but not of BMI and leptin during antiviral treatment in noncirrhotic, chronic hepatitis C genotype 1 patients who achieved EVR suggests a viral genesis of insulin resistance in patients with nonmetabolic phenotype.

  6. Genotypic Detection of rpoB and katG Gene Mutations Associated with Rifampicin and Isoniazid Resistance in Mycobacterium Tuberculosis Isolates: A Local Scenario (Kelantan).

    Science.gov (United States)

    Ismail, Nurul-Ain; Ismail, Mohd Fazli; Noor, Siti Suraiya Md; Camalxaman, Siti Nazrina

    2016-01-01

    Drug resistant tuberculosis (DR-TB) remains a public health issue that is of major concern on a global scale. The characterisation of clinical isolates may provide key information regarding the underlying mechanisms of drug resistance, and helps to augment therapeutic options. This study aims to evaluate the frequency of gene mutations associated with Rifampicin (RIF) and Isoniazid (INH) resistance among nine clinical isolates. A total of nine drug resistant Mycobacterium tuberculosis clinical isolates were screened for genetic mutations in rpoB and katusing polymerase chain reaction (PCR) amplification and DNA sequencing. Genotypic analysis was performed to detect the mutations in the sequence of the target genes. Our findings reveal that 80% of the isolates possess mutations at codon 119 (His119Tyr) and 135 (Arg135Trp and Ser135Leu) within the rpoB gene; and 70% possess mutations in the katG gene at codon 238 with amino acid change (Leu238Arg). Findings from this study provide an overview of the current situation of RIF and INH resistance in a hospital Universiti Sains Malaysia (HUSM) located in Kelantan, Malaysia, which could facilitate molecular-based detection methods of drug-resistant strains. Further information regarding the molecular mechanisms involved in resistance in RR-/MDR-TB should be addressed in the near future.

  7. Immune activation, CD4+ T cell counts, and viremia exhibit oscillatory patterns over time in patients with highly resistant HIV infection.

    Directory of Open Access Journals (Sweden)

    Christina M R Kitchen

    Full Text Available The rates of immunologic and clinical progression are lower in patients with drug-resistant HIV compared to wild-type HIV. This difference is not fully explained by viral load. It has been argued that reductions in T cell activation and/or viral fitness might result in preserved target cells and an altered relationship between the level of viremia and the rate of CD4+ T cell loss. We tested this hypothesis over time in a cohort of patients with highly resistant HIV. Fifty-four antiretroviral-treated patients with multi-drug resistant HIV and detectable plasma HIV RNA were followed longitudinally. CD4+ T cell counts and HIV RNA levels were measured every 4 weeks and T cell activation (CD38/HLA-DR was measured every 16 weeks. We found that the levels of CD4+ T cell activation over time were a strong independent predictor of CD4+ T cell counts while CD8+ T cell activation was more strongly associated with viremia. Using spectral analysis, we found strong evidence for oscillatory (or cyclic behavior in CD4+ T cell counts, HIV RNA levels, and T cell activation. Each of the cell populations exhibited an oscillatory behavior with similar frequencies. Collectively, these data suggest that there may be a mechanistic link between T cell activation, CD4+ T cell counts, and viremia and lends support for the hypothesis of altered predator-prey dynamics as a possible explanation of the stability of CD4+ T cell counts in the presence of sustained multi-drug resistant viremia.

  8. Severely Obese Adolescents and Adults Exhibit a Different Association of Circulating Levels of Adipokines and Leukocyte Expression of the Related Receptors with Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Antonello E. Rigamonti

    2013-01-01

    Full Text Available Obese adults frequently exhibit a low-grade inflammation and insulin resistance, which have been hypothesized to be established early in childhood. Aim of this study was to evaluate the age-dependent relationships between inflammatory state and insulin resistance in obese adolescents and adults. Clinical and metabolic parameters, circulating adipokines (TNF-α, adiponectin, and leptin, ghrelin, their leukocyte receptors (TNFR1, ADIPOR2, OBRL and GHSR1a, and acute phase reactants (CRP and white blood cells were assessed in lean and obese adolescents compared with the adult counterparts. Only obese adults had higher HOMA-IR, insulin, and triglycerides compared to the lean group. An inflammatory state was present in obese adolescents and adults, as demonstrated by the higher values of CRP and neutrophils. There were no group differences in circulating levels of TNF-α and leukocyte expression of TNFR1. Adiponectin concentrations and leukocyte expression of ADIPOR2 were higher in the lean groups than in the corresponding obese counterparts. For leptin and leukocyte expression of OBRL, the results were opposed. Circulating levels of ghrelin were higher in lean adolescents and adults than the related lean groups, while there was a higher leukocyte expression of GHSR1a in (only lean adults than obese adults. When the analysis was performed in (lean or obese adults, TNF-α, neutrophils, leptin, and GHSR1a were predictors of HOMA-IR. None of the considered independent variables accounted for the degree of insulin resistance in the adolescent group. In conclusion, a dissociation between the low-grade inflammation and insulin resistance is supposed to exist in the early phases of obesity.

  9. [Evaluation of the genotype MTBDR assay for rapid detection of rifampin and isoniazid resistance in clinical Mycobacterium tuberculosis complex clinical isolates].

    Science.gov (United States)

    Aslan, Gönül; Tezcan, Seda; Emekdaş, Gürol

    2009-04-01

    Rapid identification of resistant Mycobacterium tuberculosis complex isolates is quite important for the establishment of early and appropriate therapy. The Genotype MTBDR (Hain Lifescience, Nehren, Germany) is a commercially available DNA strip assay designed for the rapid detection of rpoB and katG gene mutations in clinical isolates. This study was conducted to determine the mutation types of phenotypically drug resistant 26 M. tuberculosis complex clinical isolates [15 isoniazid (INH), 1 rifampin (RMP) and 10 INH and RMP resistant] by Genotype MTBDR (G-MTBDR) DNA strip assay and to compare the diagnostic performance of this test. Sixteen of 25 (64%) INH-resistant and 9 of 11 (81.8%) RMP-resistant clinical isolates were correctly identified with the presence of hybridization in mutation probe or lack of hybridization at least by one of the wild type probes, by G-MTBDR assay. Hybridization with mutation probes was detected in only 5 of the RMP resistant isolates. We observed rpoB MUT3 (S531L, Ser-->4Leu) mutation in 4 and rpoB MUT1 (D516V) in one of these isolates. In 56% (14/25) of the INH-resistant isolates, katG T1 (S315T1) hybridization pattern was observed at katG mutation probe. G-MTBDR assay couldn't identify two of the 11 (18.2%) RMP-resistant isolates and one of these iSolates was shown to have a mutation at codon 531 (TCG-GCG) and the other at codon 545 (CTG-->ATG), possibly not associated with resistance, by sequence analysis. In four of the eight (8/25; 32%) INH-resistant isolates not identified by G-MTBDR assay, DNA cycle sequencing revealed different nucleotide changes outside the most common mutation zone. One of these were at codon 293 (GCT-->ACT) in katG, one with dual mutation at 279 (GGC-->ACC) in katG and at 15th C-->T in inhA gene, one at 15th C-->T in inhA gene and one at 279 (GGC-->ACC) in katG gene region. DNA membrane strip assay can be a use ful tool for the rapid detection of resistant M. tuberculosis complex isolates and therefore

  10. Effects of temperature on growth and photosynthesis in the seedling stage of the sheath blight-resistant rice genotype 32R

    Directory of Open Access Journals (Sweden)

    Huynh Van Kiet

    2016-04-01

    Full Text Available The 32R rice genotype is resistant to sheath blight disease (ShB, with a high-yield potential. We examined effects of temperature on the plant responses of 32R in comparison with those of the ShB-susceptible rice genotype (29S and Nipponbare (Nb, a Japonica standard cultivar. The seedlings at the 4th leaf stage of rice genotypes were exposed to 14/14, 19/14, 25/20, 31/26, 37/32 and 37/37 °C (day/night for 5, 10 and 15 days. The dry weight, leaf area, photosynthesis, contents of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco and chlorophyll contents were examined. The dry weight showed lower in 32R than in 29S and Nb at a low temperature, and total dry weight correlated strongly with root dry weight and leaf area. The relative growth rate (RGR correlated strongly with the net assimilation rate (NAR. Rubisco, chlorophyll contents and the photosynthetic rates were limited at a low temperature and showed lower in 32R than in 29S and Nb. The strong correlations between Rubisco and the rates of maximum photosynthesis and initial slope were found in 32R, but not found in 29S and Nb. In addition, RGR and NAR of 32R correlated positively with Rubisco. These suggest that 32R contains traits of cold-sensitive genotypes that are related to limiting Rubisco at a low temperature, thus diminishing photosynthesis and limiting plant growth. Differences of growth among 32R, 29S and Nb were discussed in the relation of genotypes.

  11. Analysis of phenotype, genotype and serotype distribution in erythromycin-resistant group B streptococci isolated from vaginal flora in Southern Ireland.

    LENUS (Irish Health Repository)

    Kiely, R A

    2010-02-01

    The screening of 2000 women of childbearing age in Cork between 2004 and 2006 produced 37 erythromycin-resistant group B streptococcus (GBS) isolates. PCR analysis was performed to determine the basis for erythromycin resistance. The ermTR gene was most frequently expressed (n = 19), followed by the ermB gene (n = 8). Four isolates harboured the mefA gene. Six isolates yielded no PCR products. Some phenotype-genotype correlation was observed. All isolates expressing the mefA gene displayed the M phenotype whilst all those expressing ermB displayed the constitutive macrolide resistance (cMLS(B)) phenotype. Of 19 isolates that expressed the ermTR gene, 16 displayed the inducible macrolide resistance (iMLS(B)) phenotype. Serotype analysis revealed that serotypes III and V predominated in these isolates. The identification of two erythromycin-resistant serotype VIII isolates among this collection represents the first reported finding of erythromycin resistance in this serotype. A single isolate was non-typable using two latex agglutination serotyping kits.

  12. Molecular epidemiological survey on aminoglycoside antibiotics-resistant genotype and phenotype of avian Escherichia coli in North China.

    Science.gov (United States)

    Zhang, T; Wang, C G; Jiang, G E; Lv, J C; Zhong, X H

    2012-10-01

    Monitoring drug resistance in Escherichia coli is important for prevention and treatment of colibacillosis. To choose effective drugs to prevent and control avian colibacillosis in North China, we investigated resistance of 205 E. coli isolates (from Beijing, Tianjin, inner Mongolia, Shanxi, and Hebei regions) to commonly used clinical aminoglycoside antibiotics using a drug susceptibility test. The results show that the isolates had varying degrees of resistance to kanamycin, gentamicin, streptomycin, amikacin, neomycin, and spectinomycin. Particularly, the resistance rates of the former 3 antibiotics exceeded 40%. To explore the reasons for wide drug resistance, aminoglycosides modifying enzymes (AME) genes, which are important in generation of aminoglycoside resistance, were detected by PCR. Of the isolates, 60.98% carried AME genes and 38.05% carried commensal multidrug resistance genes. Therefore, resistance of avian E. coli to aminoglycoside antibiotics is very serious in North China, perhaps due to the existence of resistance genes.

  13. Effect of end of season water deficit on phenolic compounds in peanut genotypes with different levels of resistance to drought.

    Science.gov (United States)

    Aninbon, C; Jogloy, S; Vorasoot, N; Patanothai, A; Nuchadomrong, S; Senawong, T

    2016-04-01

    Terminal drought reduces pod yield and affected the phenolic content of leaves, stems and seed of peanut (Arachis hypogaea L.). The aim of this study was to investigate the effects of end of season water deficit on phenolic content in drought tolerant and sensitive genotypes of peanuts. Five peanut genotypes were planted under two water regimes, field capacity and 1/3 available water. Phenolic content was analyzed in seeds, leaves, and stems. The results revealed that terminal drought decreased phenolic content in seeds of both tolerant and sensitive genotypes. Phenolic content in leaves and stems increased under terminal drought stress in both years. This study provides basic information on changes in phenolic content in several parts of peanut plants when subjected to drought stress. Future studies to define the effect of terminal drought stress on specific phenolic compounds and antioxidant properties in peanut are warranted.

  14. The contrasting effects of elevated CO2 on TYLCV infection of tomato genotypes with and without the resistance gene, Mi-1.2

    Directory of Open Access Journals (Sweden)

    Huijuan Guo

    2016-11-01

    Full Text Available Elevated atmospheric CO2 typically enhances photosynthesis of C3 plants and alters primary and secondary metabolites in plant tissue. By modifying the defensive signaling pathways in host plants, elevated CO2 could potentially affect the interactions between plants, viruses, and insects that vector viruses. R gene-mediated resistance in plants represents an efficient and highly specific defense against pathogens and herbivorous insects. The current study determined the effect of elevated CO2 on tomato plants with and without the R gene Mi-1.2 and the subsequent effect on the severity of TYLCV and the performance of the vector, Bemisia tabaci. The results showed that elevated CO2 increased the biomass, plant height, and photosynthetic rate of both the wild-type and the Mi-1.2 genotype. Elevated CO2 decreased TYLCV disease incidence and severity for wild-type plants but had the opposite effect on Mi-1.2 plants whether the plants were artificially inoculated or inoculated via B. tabaci feeding. Elevated CO2 increased the salicylic acid (SA-dependent signaling pathway on wild-type plants but decreased the SA signaling pathway on Mi-1.2 plants when infected by TYLCV. Elevated CO2 did not significantly affect B. tabaci fitness or the ability of viruliferous B. tabaci to transmit virus regardless of plant genotype. The results indicate that elevated CO2 increases the resistance of wild-type plants but decreases the resistance of Mi-1.2 plants against TYLCV, whether the plants are artificially inoculated or inoculated by the vector. Our results suggest that plant genotypes containing the R gene Mi-1.2 will be more vulnerable to TYLCV and perhaps to other plant viruses under elevated CO2 conditions.

  15. Differential Space-Time Expression of StLTPb1 Gene Between Resistant and Susceptible Potato Genotypes in Response to Ralstonia solanacearum

    Institute of Scientific and Technical Information of China (English)

    GAO Gang; JIN Li-ping; XIE Kai-yun; QU Dong-yu

    2008-01-01

    This study is to investigate the role of lipid transfer protein (LTP1) gene of potato (Solanum tuberosum) in bacterial wilt (Ralstonia solanacearum) resistance. A novel cDNA clone encoding nsLTP was isolated from cultivated potato (Solanum tuberosum) infected with R. solanacearum by 5'-rapid amplification of cDNA ends (RACE). The temporal and spatial expression of StLTPb1 was studied during the early stages of potato-R. solanacearum interaction by reverse transcriptase PCR (RT-PCR) and Northern blotting. The sequence analysis of the cloned cDNA, named StLTPb1, showed 691 bp which encoded a type 1 nsLTP of 91 amino acids. Construction of a phylogenic tree showed that StLTPb1 is well conserved in the coding region with high identity at the amino acid level with other Solanaceae nsLTPs. The temporal and spatial expression of StLTPb1 was studied during the early stages of potato-R, solanacearum interaction. StLTPb1 transcription is induced faster and transcripts accumulate to higher concentrations in resistant compared with susceptible genotypes by the pathogen. Dominant differences in the pathogen-induced gene expression pattern between the upper and lower leaves and stems were observed within the same genotypes. In situ hybridization results showed that the StLTPb1 mRNA was localized in phloem cells of vascular tissues in potato leaf and stem tissues after pathogen infection. Salicylic acid, methyl jasmonate and abscisic acid could induce StLTPb1 gene expression without significant difference between the upper and lower tissues. These abiotic elicitors could produce a long-lasting effect on the StLTPb1 during early stages of potato-R. solanacearum interaction. Differential expression of StLTPb1 gene between resistance and susceptible potato genotypes in response to R. solanacearum suggests that this gene plays a key role in plant defense mechanisms.

  16. Identification of Loci Associated with Drought Resistance Traits in Heterozygous Autotetraploid Alfalfa (Medicago sativa L. Using Genome-Wide Association Studies with Genotyping by Sequencing.

    Directory of Open Access Journals (Sweden)

    Tiejun Zhang

    Full Text Available Drought resistance is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. Identification of genes involved in drought tolerance will facilitate breeding for improving drought resistance and water use efficiency in alfalfa. Our objective was to use a diversity panel of alfalfa accessions comprised of 198 cultivars and landraces to identify genes involved in drought tolerance. The panel was selected from the USDA-ARS National Plant Germplasm System alfalfa collection and genotyped using genotyping by sequencing. A greenhouse procedure was used for phenotyping two important traits associated with drought tolerance: drought resistance index (DRI and relative leaf water content (RWC. Marker-trait association identified nineteen and fifteen loci associated with DRI and RWC, respectively. Alignments of target sequences flanking to the resistance loci against the reference genome of M. truncatula revealed multiple chromosomal locations. Markers associated with DRI are located on all chromosomes while markers associated with RWC are located on chromosomes 1, 2, 3, 4, 5, 6 and 7. Co-localizations of significant markers between DRI and RWC were found on chromosomes 3, 5 and 7. Most loci associated with DRI in this work overlap with the reported QTLs associated with biomass under drought in alfalfa. Additional significant markers were targeted to several contigs with unknown chromosomal locations. BLAST search using their flanking sequences revealed homology to several annotated genes with functions in stress tolerance. With further validation, these markers may be used for marker-assisted breeding new alfalfa varieties with drought resistance and enhanced water use efficiency.

  17. Identification of Loci Associated with Drought Resistance Traits in Heterozygous Autotetraploid Alfalfa (Medicago sativa L.) Using Genome-Wide Association Studies with Genotyping by Sequencing.

    Science.gov (United States)

    Zhang, Tiejun; Yu, Long-Xi; Zheng, Ping; Li, Yajun; Rivera, Martha; Main, Dorrie; Greene, Stephanie L

    2015-01-01

    Drought resistance is an important breeding target for enhancing alfalfa productivity in arid and semi-arid regions. Identification of genes involved in drought tolerance will facilitate breeding for improving drought resistance and water use efficiency in alfalfa. Our objective was to use a diversity panel of alfalfa accessions comprised of 198 cultivars and landraces to identify genes involved in drought tolerance. The panel was selected from the USDA-ARS National Plant Germplasm System alfalfa collection and genotyped using genotyping by sequencing. A greenhouse procedure was used for phenotyping two important traits associated with drought tolerance: drought resistance index (DRI) and relative leaf water content (RWC). Marker-trait association identified nineteen and fifteen loci associated with DRI and RWC, respectively. Alignments of target sequences flanking to the resistance loci against the reference genome of M. truncatula revealed multiple chromosomal locations. Markers associated with DRI are located on all chromosomes while markers associated with RWC are located on chromosomes 1, 2, 3, 4, 5, 6 and 7. Co-localizations of significant markers between DRI and RWC were found on chromosomes 3, 5 and 7. Most loci associated with DRI in this work overlap with the reported QTLs associated with biomass under drought in alfalfa. Additional significant markers were targeted to several contigs with unknown chromosomal locations. BLAST search using their flanking sequences revealed homology to several annotated genes with functions in stress tolerance. With further validation, these markers may be used for marker-assisted breeding new alfalfa varieties with drought resistance and enhanced water use efficiency.

  18. Scrapie prevalence in sheep of susceptible genotype is declining in a population subject to breeding for resistance

    NARCIS (Netherlands)

    Hagenaars, T.H.J.; Melchior, M.B.; Bossers, A.; Davidse, A.; Engel, B.; Zijderveld, van F.G.

    2010-01-01

    Background - Susceptibility of sheep to scrapie infection is known to be modulated by the PrP genotype of the animal. In the Netherlands an ambitious scrapie control programme was started in 1998, based on genetic selection of animals for breeding. From 2002 onwards EU regulations required intensive

  19. A Systematic Follow-Up of Mycobacterium tuberculosis Drug-Resistance and Associated Genotypic Lineages in the French Departments of the Americas over a Seventeen-Year Period

    Directory of Open Access Journals (Sweden)

    Julie Millet

    2014-01-01

    Full Text Available The population of the French Departments of the Americas (FDA is highly influenced by the intense migratory flows with mainland France and surrounding countries of the Caribbean and Latin America, some of which have high incidence rates of tuberculosis (Haiti: 230/100,000; Guyana: 111/100,000; and Suriname: 145/100,000 and drug resistance. Since the development of drug resistance to conventional antituberculous drugs has a major impact on the treatment success of tuberculosis, we therefore decided to review carefully Mycobacterium tuberculosis drug resistance and associated genotypic lineages in the FDA over a seventeen-year period (January 1995–December 2011. A total of 1239 cases were studied, including 153 drug-resistant and 26 multidrug-resistant- (MDR- TB cases, representing 12.3% and 2.1% of the TB cases in our study setting. A significantly higher proportion of M. tuberculosis isolates among relapse cases showed drug resistance to isoniazid (22.5%, P=0.002, rifampicin (20.0%, P<0.001, or both (MDR-TB, 17.5%; P<0.001. Determination of spoligotyping based phylogenetic clades showed that among the five major lineages observed—T family (30.1%; Latin-American and Mediterranean (LAM, 23.7%; Haarlem (H, 22.2%; East-African Indian (EAI, 7.2%; and X family (6.5%—two lineages, X and LAM, were overrepresented in drug-resistant and MDR-TB cases, respectively. Finally, 19 predominant spoligotypes were identified for the 1239 isolates of M. tuberculosis in our study among which 4 were significantly associated with drug resistance corresponding to SIT20/LAM1, SIT64/LAM6, SIT45/H1, and SIT46/undefined lineage.

  20. Trends in Genotypic HIV-1 Antiretroviral Resistance between 2006 and 2012 in South African Patients Receiving First- and Second-Line Antiretroviral Treatment Regimens.

    Directory of Open Access Journals (Sweden)

    Gert U Van Zyl

    Full Text Available South Africa's national antiretroviral (ARV treatment program expanded in 2010 to include the nucleoside reverse transcriptase (RT inhibitors (NRTI tenofovir (TDF for adults and abacavir (ABC for children. We investigated the associated changes in genotypic drug resistance patterns in patients with first-line ARV treatment failure since the introduction of these drugs, and protease inhibitor (PI resistance patterns in patients who received ritonavir-boosted lopinavir (LPV/r-containing therapy.We analysed ARV treatment histories and HIV-1 RT and protease mutations in plasma samples submitted to the Tygerberg Academic Hospital National Health Service Laboratory.Between 2006 and 2012, 1,667 plasma samples from 1,416 ARV-treated patients, including 588 children and infants, were submitted for genotypic resistance testing. Compared with 720 recipients of a d4T or AZT-containing first-line regimen, the 153 recipients of a TDF-containing first-line regimen were more likely to have the RT mutations K65R (46% vs 4.0%; p<0.001, Y115F (10% vs. 0.6%; p<0.001, L74VI (8.5% vs. 1.8%; p<0.001, and K70EGQ (7.8% vs. 0.4% and recipients of an ABC-containing first-line regimen were more likely to have K65R (17% vs 4.0%; p<0.001, Y115F (30% vs 0.6%; p<0.001, and L74VI (56% vs 1.8%; p<0.001. Among the 490 LPV/r recipients, 55 (11% had ≥1 LPV-resistance mutations including 45 (9.6% with intermediate or high-level LPV resistance. Low (20 patients and intermediate (3 patients darunavir (DRV cross resistance was present in 23 (4.6% patients.Among patients experiencing virological failure on a first-line regimen containing two NRTI plus one NNRTI, the use of TDF in adults and ABC in children was associated with an increase in four major non- thymidine analogue mutations. In a minority of patients, LPV/r-use was associated with intermediate or high-level LPV resistance with predominantly low-level DRV cross-resistance.

  1. Antimicrobial susceptibility of Streptococcus pneumoniae and genotypic characterization of erythromycin-resistant strains in Porto Alegre, Brazil

    Directory of Open Access Journals (Sweden)

    F. T. Weber

    2010-03-01

    Full Text Available The antimicrobial susceptibility of 64 strains of S. pneumoniae obtained from three hospitals in Porto Alegre, Brazil, isolated between 2004 and 2005, was determined, using the agar-dilution method. The prevalence of resistant (intermediate and full resistance strains to trimethoprim/sulphamethoxazole, penicillin, tetracycline, erythromycin, chloramphenicol, and ceftriaxone were 68%, 28%, 18%, 15%, 3%, and 1%, respectively. All strains were susceptible to vancomycin. Among 18 penicillin-resistant strains, 7 were resistant to at least two other antimicrobial drugs. All erythromycin-resistant strains, except one, contained the erm(B and/or mef(A/E genes, with a predominance of the former. The resistance rate to penicillin and erythromycin in Porto Alegre remained stable. The combination of trimethoprim/ sulphamethoxazole should not be recommended to treat pneumococcal infections, because of the high rate of resistant strains.

  2. GenoType MTBDRsl for molecular detection of second-line-drug and ethambutol resistance in Mycobacterium tuberculosis strains and clinical samples.

    Science.gov (United States)

    Lacoma, A; García-Sierra, N; Prat, C; Maldonado, J; Ruiz-Manzano, J; Haba, L; Gavin, P; Samper, S; Ausina, V; Domínguez, J

    2012-01-01

    The purpose of this study was to evaluate the GenoType MTBDRsl assay (Hain Lifescience GmbH, Nehren, Germany) for its ability to detect resistance to fluoroquinolones (FLQ), injectable second-line antibiotics [kanamycin (KM) and capreomycin (CM)], and ethambutol (EMB) in Mycobacterium tuberculosis clinical strains and directly in clinical samples. A total of 34 clinical strains were characterized with the Bactec 460 TB system. Fifty-four clinical samples from 16 patients (5 were smear negative and 49 were smear positive) were also tested directly. The corresponding isolates of the clinical specimens were also analyzed with the Bactec 460TB. When there was a discrepancy between assays, pyrosequencing was performed. The overall rates of concordance of the MTBDRsl and the Bactec 460TB for the detection of FLQ, KM/CM, and EMB susceptibility in clinical strains were 72.4% (21/29), 88.8% (24/27), and 67.6% (23/34), whereas for clinical samples, rates were 86.5% (45/52), 92.3% (48/52), and 56% (28/50), respectively. In conclusion, the GenoType MTBDRsl assay may be a useful tool for making early decisions regarding KM/CM susceptibility and to a lesser extent regarding FLQ and EMB susceptibility. The test is able to detect mutations in both clinical strains and samples with a short turnaround time. However, for correct management of patients with extensively drug-resistant tuberculosis, results must be confirmed by a phenotypical method.

  3. Inactivated chimeric porcine circovirus (PCV) 1-2 vaccines based on genotypes 2b and 2d exhibit similar immunological effectiveness in protecting pigs against challenge with PCV2b strain 0233.

    Science.gov (United States)

    Li, Jizong; Yu, Tianqi; Zhang, Feipeng; Wang, Xiaobo; Zhou, Jinzhu; Gao, Xing; Gao, Song; Liu, Xiufan

    2017-01-01

    Porcine circovirus type 2 (PCV2) is subdivided into four genotypes: PCV2a, PCV2b, PCV2c and PCV2d. Here, for the first time, we compared the efficacy of two experimental inactivated chimeric PCV1-2 vaccines based on genotypes 2b and 2d. Seventeen 3-week-old pigs were divided randomly into four groups. Group 1 and 2 pigs were inoculated with genotype 2b- and 2d-based inactivated vaccines, respectively. At 28 days post-vaccination (DPV), pigs in groups 1-3 were challenged with the PCV2b 0233 strain. All experimental pigs were necropsied at 21 days post-challenge (DPC). Pigs vaccinated with the genotype 2b- or 2d-based vaccine had high antibody titres and lower PCV2b copy numbers in samples of sera, faeces and nasal secretions compared with pigs in the unvaccinated challenge group. Interestingly, we detected no DNA from the challenge strain in the superficial inguinal lymph nodes of the pigs immunized with the PCV2b vaccine, while one pig in the PCV2d- immunized group had detectable DNA from the challenge strain at 21 DPC. We found no significant differences in the humoral immune response, PCV2b load, or PCV-related microscopic lesions between the two vaccinated groups post-challenge. Therefore, both vaccines were equally effective at inducing immunity against challenge with PCV2b strain 0233.

  4. Russian gonococcal antimicrobial susceptibility programme (RU-GASP) – resistance in Neisseria gonorrhoeae during 2009–2012 and NG-MAST genotypes in 2011 and 2012

    Science.gov (United States)

    2014-01-01

    Background Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a major concern worldwide and gonococcal AMR surveillance globally is imperative for public health purposes. In Eastern Europe, gonococcal AMR surveillance is exceedingly rare. However, in 2004 the Russian gonococcal antimicrobial susceptibility programme (RU-GASP) was initiated. The aims of this study were to describe the prevalence and trends of gonococcal AMR from 2009 to 2012, and molecular epidemiological genotypes in 2011 and 2012 in Russia. Methods Gonococcal isolates from 12–46 surveillance sites distributed across Russia, obtained in 2009 (n = 1200), 2010 (n = 407), 2011 (n = 423), and 2012 (n = 106), were examined for antimicrobial susceptibility using agar dilution method. Gonococcal isolates from 2011 and 2012 were investigated with N. gonorrhoeae multi-antigen sequence typing (NG-MAST). Results During 2009–2012, the proportions of gonococcal isolates resistant to ciprofloxacin, penicillin G, azithromycin and spectinomycin ranged from 25.5% to 44.4%, 9.6% to 13.2%, 2.3% to 17.0% and 0.9% to 11.6%, respectively. Overall, the resistance level to penicillin G was stable, the resistance level to ciprofloxacin was decreasing, however, the level of resistance to azithromycin increased. All isolates were susceptible to ceftriaxone using the US CLSI breakpoints. However, using the European breakpoints 58 (2.7%) of the isolates were resistant to ceftriaxone. Interestingly, this proportion was decreasing, i.e. from 4.8% in 2009 to 0% in 2012. Conclusions In Russia, the diversified gonococcal population showed a high resistance to ciprofloxacin, penicillin G and azithromycin. In general, the MICs of ceftriaxone were relatively high, however, they were decreasing from 2009 to 2012. Ceftriaxone should be the first-line for empiric antimicrobial monotherapy of gonorrhoea in Russia. It is essential to further strengthen the surveillance of gonococcal AMR (ideally also gonorrhoea

  5. Russian gonococcal antimicrobial susceptibility programme (RU-GASP)--resistance in Neisseria gonorrhoeae during 2009-2012 and NG-MAST genotypes in 2011 and 2012.

    Science.gov (United States)

    Kubanova, Anna; Kubanov, Alexey; Frigo, Nataliya; Solomka, Viktoria; Semina, Vera; Vorobyev, Denis; Khairullin, Rafil; Unemo, Magnus

    2014-06-19

    Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a major concern worldwide and gonococcal AMR surveillance globally is imperative for public health purposes. In Eastern Europe, gonococcal AMR surveillance is exceedingly rare. However, in 2004 the Russian gonococcal antimicrobial susceptibility programme (RU-GASP) was initiated. The aims of this study were to describe the prevalence and trends of gonococcal AMR from 2009 to 2012, and molecular epidemiological genotypes in 2011 and 2012 in Russia. Gonococcal isolates from 12-46 surveillance sites distributed across Russia, obtained in 2009 (n = 1200), 2010 (n = 407), 2011 (n = 423), and 2012 (n = 106), were examined for antimicrobial susceptibility using agar dilution method. Gonococcal isolates from 2011 and 2012 were investigated with N. gonorrhoeae multi-antigen sequence typing (NG-MAST). During 2009-2012, the proportions of gonococcal isolates resistant to ciprofloxacin, penicillin G, azithromycin and spectinomycin ranged from 25.5% to 44.4%, 9.6% to 13.2%, 2.3% to 17.0% and 0.9% to 11.6%, respectively. Overall, the resistance level to penicillin G was stable, the resistance level to ciprofloxacin was decreasing, however, the level of resistance to azithromycin increased. All isolates were susceptible to ceftriaxone using the US CLSI breakpoints. However, using the European breakpoints 58 (2.7%) of the isolates were resistant to ceftriaxone. Interestingly, this proportion was decreasing, i.e. from 4.8% in 2009 to 0% in 2012. In Russia, the diversified gonococcal population showed a high resistance to ciprofloxacin, penicillin G and azithromycin. In general, the MICs of ceftriaxone were relatively high, however, they were decreasing from 2009 to 2012. Ceftriaxone should be the first-line for empiric antimicrobial monotherapy of gonorrhoea in Russia. It is essential to further strengthen the surveillance of gonococcal AMR (ideally also gonorrhoea treatment failures) in Russia.

  6. Comparative Phenotypic and Genotypic Analysis of Swiss and Finnish Listeria monocytogenes Isolates with Respect to Benzalkonium Chloride Resistance.

    Science.gov (United States)

    Meier, Anja B; Guldimann, Claudia; Markkula, Annukka; Pöntinen, Anna; Korkeala, Hannu; Tasara, Taurai

    2017-01-01

    Reduced susceptibility of Listeria monocytogenes to benzalkonium chloride (BC), a quaternary ammonium compound widely used in food processing and hospital environments, is a growing public health and food safety concern. The minimal inhibitory concentration of BC on 392 L. monocytogenes strains from Switzerland (CH) and Finland (FIN) was determined. Within this strain collection, benzalkonium chloride resistance was observed in 12.3% (24/195) of Swiss and 10.6% (21/197) of Finnish strains. In both countries, the highest prevalence of BC-resistant strains (CH: 29.4%; FIN: 38.9%) was detected among serotype 1/2c strains. Based on PCR analysis, genes coding for the qacH efflux pump system were detected for most of the BC-resistant strains (CH: 62.5%; FIN: 52.4%). Some Swiss BC-resistant strains harbored genes coding for the bcrABC (16.7%) efflux pump system, while one Finnish BC-resistant strain harbored the emrE gene previously only described among BC-resistant L. monocytogenes strains from Canada. Interestingly, a subset of BC-resistant strains (CH: 5/24, 20.8%; FIN: 9/21, 42.8%) lacked genes for efflux pumps currently known to confer BC resistance in L. monocytogenes. BC resistance analysis in presence of reserpine showed that the resistance was completely or partially efflux pump dependent in 10 out of the 14 strains lacking the known BC resistance genes. Sequence types 155 and ST403 were over-representated among these strains suggesting that these strains might share similar but yet unknown mechanisms of BC resistance.

  7. Resistance of tomato genotypes to the silverleaf whitefly mediated by acylsugars Resistência de genótipos de tomateiro a Bemisia tabaci biótipo B, mediada por acilaçúcares

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    Juliano TV de Resende

    2009-09-01

    Full Text Available Acylsugars in the leaflets of the wild accession LA-716 (Lycopersicon pennellii gives resistance to Bemisia spp., which causes expressive losses to the tomato crop. The goal of this work was to evaluate the resistance to the silverleaf whitefly (Bemisia tabaci biotype B of previously selected genotypes, based on the level of acylsugars in the leaflets. F2BC1 plants {F2[Lycopersicon esculentum TOM 584 x (L. esculentum TOM 584 x L. pennellii LA-716]} were selected for extreme contents of acylsugars: BPX-370B pl#30-275, BPX-370B pl#79-278, BPX-370B pl#30-380, BPX-370B pl#25-271 (high contents, BPX-370B pl#30-02, BPX-370B pl#30-142 (low contents. These genotypes, along with the parents TOM 584 and LA-716, were submitted to a silverleaf whitefly infestation. Oviposition and nymph development were evaluated. The oviposition on the genotypes BPX-370B pl#30-275 and BPX-370B pl#30-380 was significantly lower to that which occurred on the genotype TOM 584 and in the other genotypes of the F2RC1 generation. The four genotypes selected for high acylsugar contents presented the lowest number of nymphs, except to LA-716. Although the number of eggs in the BPX-370B pl#25-271 and BPX-370B pl#79-278 genotypes (high contents was elevated, the number of nymphs was reduced, similarly to the other high-acylsugar genotypes, probably due to antibioses effect.Acilaçúcares presentes nos folíolos do acesso selvagem 'LA-716' (Lycopersicon pennellii conferem resistência a moscas-brancas (Bemisia spp., causadoras de danos expressivos à cultura do tomate. O objetivo do trabalho foi avaliar a resistência de genótipos de tomateiro à mosca-branca Bemisia tabaci biótipo B, com base nos teores de acilaçúcares nos folíolos. Foram selecionadas plantas F2RC1{[L. esculentum 'TOM-584' x (L. esculentum 'TOM-584' x L. pennellii 'LA-716']} para teores extremos de acilaçúcares: BPX-370B pl#30-275, BPX-370B pl#79-278, BPX-370B pl#30-380, BPX-370B pl#25-271 (altos teores, BPX

  8. Inference of Antibiotic Resistance and Virulence Among Diverse Group A Streptococcus Strains Using emm Sequencing and Multilocus Genotyping Methods

    Science.gov (United States)

    2009-09-04

    pneumonia . Less frequently, it can cause severe symptoms such as toxic shock syndrome, necrotizing fasciitis, and sterile rheumatic sequelae [1]. Penicillin ... Pneumonia outbreak associated with group A Streptococcus at a military training facility. Clin Infect Dis 40: 511–518. 17. Lamagni TL, Neal S, Keshishian C...Macrolide resistance and erythromycin resistance determinants among Belgian Streptococcus pyogenes and Streptococcus pneumoniae isolates. J Antimicrob

  9. Biology of Anticarsia gemmatalis on soybean genotypes with different degrees of resistance to insects Biologia de Anticarsia gemmatalis em genótipos de soja com diferentes graus de resistência a insetos

    Directory of Open Access Journals (Sweden)

    Cristina Gomes Quevedo Fugi

    2005-01-01

    Full Text Available A knowledge of the mechanisms of resistance present in genetic materials should help breeding programs in developing cultivars resistant to insects. The biology of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae was studied on leaves of four soybean genotypes with different degrees of resistance to insects. The genotypes evaluated were cultivars IAC 17 and IAC 24, resistant to defoliators and stink bugs, line PI 229358, a source of multiple resistance to insects and used as parent in various lines selected for resistance to A. gemmatalis, and 'IAC PL-1', the susceptible control. The experiments were carried out in the laboratory, under controlled conditions of temperature (25 ± 2ºC, relative humidity (60 ± 10% and photoperiod (14h. First instar larvae were placed in Petri dishes and fed leaves of each genotype, detached from plants at the R1 and R2 stages (beginning and full bloom. Later on, insect couples were maintained in 25 PVC cages to evaluate parameters of the adult stage. 'IAC 17' and 'IAC 24' promoted low viability of the larval, pupal, and egg stages, causing adult deformation and a reduction of the number of eggs per female. PI 229358 prolonged the immature stage and reduced pupal weight, egg viability, and adult longevity. Considering all tests, 'IAC 17' and 'IAC 24' were characterized as having antibiosis-type resistance, and 'IAC PL-1' demonstrated to be a genotype suitable for insect development.O conhecimento do tipo de resistência presente em genótipos pode dinamizar programas de melhoramento que tenham essa finalidade. Assim, estudaram-se aspectos biológicos de Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae em folhas de quatro genótipos de soja, sendo três com diferentes níveis de resistência e um suscetível a insetos. Avaliaram-se os cultivares IAC 17 e IAC 24, portadores de resistência a desfolhadores e sugadores, a linhagem PI 229358, progenitora de diversas linhagens resistentes a A. gemmatalis, e

  10. Identification, genotypic relation, and clinical features of colistin-resistant isolates of Acinetobacter genomic species 13BJ/14TU from bloodstreams of patients in a university hospital.

    Science.gov (United States)

    Lee, Seung Yeob; Shin, Jong Hee; Park, Kyung Hwa; Kim, Ju Hee; Shin, Myung Geun; Suh, Soon Pal; Ryang, Dong Wook; Kim, Soo Hyun

    2014-03-01

    Colistin resistance remains rare among clinical isolates of Acinetobacter species. We noted the emergence of colistin-resistant bloodstream isolates of the Acinetobacter genomic species (GS) 13BJ/14TU from patients at a university hospital between 2003 and 2011. We report here, for the first time, the microbiological and molecular characteristics of these isolates, with clinical features of Acinetobacter GS 13BJ/14TU bacteremia. All 11 available patient isolates were correctly identified as Acinetobacter GS 13BJ/14TU using partial rpoB gene sequencing but were misidentified using the phenotypic methods Vitek 2 (mostly as Acinetobacter baumannii), MicroScan (mostly as A. baumannii/Acinetobacter haemolyticus), and the API 20 NE system (all as A. haemolyticus). Most isolates were susceptible to commonly used antibiotics, including carbapenems, but all were resistant to colistin, for which it is unknown whether the resistance is acquired or intrinsic. However, the fact that none of the patients had a history of colistin therapy strongly suggests that Acinetobacter GS 13BJ/14TU is innately resistant to colistin. The phylogenetic tree of multilocus sequence typing (MLST) showed that all 11 isolates formed a separate cluster from other Acinetobacter species and yielded five sequence types. However, pulsed-field gel electrophoresis (PFGE) revealed 11 distinct patterns, suggesting that the bacteremia had occurred sporadically. Four patients showed persistent bacteremia (6 to 17 days), and all 11 patients had excellent outcomes with cleared bacteremia, suggesting that patients with Acinetobacter GS 13BJ/14TU-associated bacteremia show a favorable outcome. These results emphasize the importance of precise species identification, especially regarding colistin resistance in Acinetobacter species. In addition, MLST offers another approach to the identification of Acinetobacter GS 13BJ/14TU, whereas PFGE is useful for genotyping for this species.

  11. Fluorescent amplified fragment length polymorphism (FAFLP genotyping demonstrates the role of biofilm-producing methicillin-resistant periocular Staphylococcus epidermidis strains in postoperative endophthalmitis

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    Hasnain Seyed E

    2006-01-01

    Full Text Available Abstract Background An observational case series was used to study the virulence characteristics and genotypes of paired Staphylococcus epidermidis isolates cultured from intraocular samples and from periocular environment of patients with postcataract surgery endophthalmitis. Methods Eight S. epidermidis isolates were obtained from three patients (2 from patients #1 and 2 and 4 from patient #3 whose vitreous and/or anterior chamber (AC specimens and preoperative lid/conjunctiva samples were culture positive. Cultures were identified by API-Staph phenotypic identification system and genotypically characterized by Fluorescent Amplified Fragment Length Polymorphism (FAFLP and checked for their antimicrobial susceptibility. The isolates were tested for biofilm-production and methicillin-resistance (MR by PCR amplification of icaAB and mecA gene respectively. Results Four out of eight S. epidermidis strains showed multiple drug resistance (MDR. All the eight strains were PCR positive for mecA gene whereas seven out of eight strains were positive for icaAB genes. In all three patients FAFLP typing established vitreous isolates of S. epidermidis strains to be indistinguishable from the strains isolated from the patient's conjunctival swabs. However, from patient number three there was one isolate (1030b from lid swab, which appeared to be nonpathogenic and ancestral having minor but significant differences from other three strains from the same patient. This strain also lacked icaAB gene. In silico analysis indicated possible evolution of other strains from this strain in the patient. Conclusion Methicillin-resistant biofilm positive S. epidermidis strains colonizing the conjunctiva and eyelid were responsible for postoperative endophthalmitis (POE.

  12. Research on the drug-resistant genotypes of hepatitis B virus in patients with chronic hepatitis B%慢性乙型肝炎患者乙型肝炎病毒耐药基因型研究

    Institute of Scientific and Technical Information of China (English)

    张书楠; 林卓玲; 余文辉; 周大桥; 张春雷; 冯玉丽; 贺劲松; 周小梅; 李伟雄; 陈雪红

    2011-01-01

    目的 研究乙型肝炎病毒(HBV)基因型与耐药病毒株产生的相关性.方法 收集85例接受拉米夫定治疗1年以上的慢性乙型肝炎(CHB)患者为研究对象.采集血样经离心分离血浆,进行HBV DNA定量检测,再进行基因测序和基因分型.结果 基因测序和基因型分析结果为A型4例(4.7%),B型28例(32.9%),C型37例(43.5%),D型11例(12.9%),B/C混合型5例(5.9%).其中发生YMDD耐药突变的基因型突变率分别是A型1例(25.0%),B型5例(17.9%),C型16例(43.2%),D型2例(18.2%),B/C混合型1例(20.0%).结论 HBV基因型C型发生YMDD耐药突变的频率较高,HBV基因型与YMDD突变可能存在相关性.%Objective To explore the correlation between hepatitis B virus (HBV) genotypes and the resistance to lamivudine (LAM). Methods 85 cases of patients with chronic hepatitis B(CHB),who had received LAM therapy for more than one year, were recruited. HBV DNA in blood samples of the 85 patients were quantitatively detected,sequenced and genotype were analyzed. Results Sequencing and genotyping revealed that 4(4. 7%) cases were with genotype A,28(32. 9%) with genotype B,37(43. 5%) with genotype C,11(12. 9%) with genotype D and 5(5. 9%) with mixed genotype B/C. The frequency of mutations in YMDD motif in patients with genotype A was 25. 0%, with genotype B was 17. 9%, with genotype C was 43. 2%, with genotype D was 18. 2% and with mixed genotype B/C was 20. 0% respectively. Conclusion The frequency of mutations in YMDD motif in HBV genotype C could be higher than that in the other genotypes. It might be deduced that there could be a correlation between HBV genotypes and mutations in YMDD motif of HBV DNA.

  13. Identification and analysis of host plant resistance in leading maize genotypes against spotted stem borer, Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Arabjafari, K H; Jalali, S K

    2007-06-01

    Twenty six popular varieties of maize in Karnataka state (India) were screened for resistance to Chilo partellus (Swinhoe). In field trial, varieties CM132, CM137 and PMZ103 showed the highest level of resistance, respectively. While the varieties GK3014, HY4642 and DK984 had the lowest level of resistance, respectively. In glasshouse trial, the varieties CM137 and HY4642 had the highest and lowest level of resistance. A positive correlation equal to +0.111 (in field) and +0.521 (in glasshouse) was found between the Leaf Injury Score (LIS) and Stem Diameter (SD). Meanwhile, negative correlation equal to -0.432 (in field) and -0.896 (in glasshouse) was found between Leaf Injury Score (LIS) and Internodal Distance (InD). Results of the studies on major nutritional elements on resistant variety CM137 and susceptible variety HY4642 indicated higher percentage of P, K, Fe and Si in stem tissues of the variety CM137, while the variety HY4642 had higher percentage of N and Sugar, highlighting the role of these elements in conferring resistance and susceptibility to C. partellus. Studies on the impact of resistance factors on biological events of C. partellus revealed significant differences between percentage survival of larvae, percentage of pupation, pupal weight and pupal period (females only) on two varieties CM137 and HY4642. But there was no significant difference in the percentage of moth emergence on two varieties.

  14. Molecular epidemiology and distribution of serotypes, genotypes, and antibiotic resistance genes of Streptococcus agalactiae clinical isolates from Guelma, Algeria and Marseille, France.

    Science.gov (United States)

    Bergal, A; Loucif, L; Benouareth, D E; Bentorki, A A; Abat, C; Rolain, J-M

    2015-12-01

    This study describes, for the first time, the genetic and phenotypic diversity among 93 Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected from Guelma, Algeria and Marseille, France. All strains were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The molecular support of antibiotic resistance and serotyping were investigated by polymerase chain reaction (PCR). The phylogenetic lineage of each GBS isolate was determined by multilocus sequence typing (MLST) and grouped into clonal complexes (CCs) using eBURST. The isolates represented 37 sequence types (STs), 16 of which were novel, grouped into five CCs, and belonging to seven serotypes. Serotype V was the most prevalent serotype in our collection (44.1%). GBS isolates of each serotype were distributed among multiple CCs, including cps III/CC19, cps V/CC1, cps Ia/CC23, cps II/CC10, and cps III/CC17. All isolates presented susceptibility to penicillin, whereas resistance to erythromycin was detected in 40% and tetracycline in 82.2% of isolates. Of the 37 erythromycin-resistant isolates, 75.7% showed the macrolide-lincosamide-streptogramin B (MLSB)-resistant phenotype and 24.3% exhibited the macrolide (M)-resistant phenotype. Constitutive MLSB resistance (46%) mediated by the ermB gene was significantly associated with the Guelma isolates, whereas the M resistance phenotype (24.3%) mediated by the mefA/E gene dominated among the Marseille isolates and belonged to ST-23. Tetracycline resistance was predominantly due to tetM, which was detected alone (95.1%) or associated with tetO (3.7%). These results provide epidemiological data in these regions that establish a basis for monitoring increased resistance to erythromycin and also provide insight into correlations among clones, serotypes, and resistance genes.

  15. Reação de resistência de genótipos de tomateiro (Lycopersicum spp. à infecção por Rhizoctonia solani Kuhn Resistance reaction of tomato genotypes (Lycopersicum spp. to Rhizoctonia solani Kuhn

    Directory of Open Access Journals (Sweden)

    A.M. Rodrigues Cassiolato

    1994-12-01

    Full Text Available Dada a importância da tomaticultura no Brasil e das enfermidades que atacam esta cultura, da mesma forma que visando futuros estados em programas de melhoramento vegetal para resistência à patógenos, este trabalho teve por objetivos: avaliar o grau de patogenicidade de quatro isolados de Rhizoctonia solani obtidos de plantas doentes de tomateiro (RT, berinjelas (RB1 e RB2 e pimentão (RP, em viveiros, frente a 9 genótipos de tomateiros e avaliar a reação de resistência de 73 genótipos de tomateiros ao R. solani. Nos experimentos utilizou-se solo esterilizado, em condições de casa de vegetação. Para o experimento I, os isolados de R. solani, oriundos das plantas de tomateiro (RT e berinjela (RB, foram igualmente mais patogênicos que os isolados de berinjela (RB, e pimentão (RP, com relação aos 9 genótipos de tomateiro testados. Pode-se dizer que os isolados variaram em graus de agressividade. Quanto às reações de resistência a R. solani, observou-se que os diferentes genótipos não diferiram estatisticamente entre si. Com relação ao experimento II, entre os 73 genótipos de tomateiro (incluindo espécies selvagens, variedades nacionais e introduções, pode-se observar que houve grande variabilidade quanto a reação de resistência a R. solani (isolado do tomateiro - RT, com percentuais de sobrevivência de plantas variando de 91%, para a cultivar Quinck Pick, até 0% de sobrevivência para o genótipo LA-462. Não foi verificada imunidade em nenhum material avaliado e sim níveis de resistência, onde esta, expressa em percentagem de sobrevivência, ocorreu de uma maneira contínua, desde uma reação de suscetibilidade até altos níveis de resistência.The present study was undertaken with the following objectives: 1 to evaluate the level of pathogenicity of four Rhizoctonia solani isolates obtained from diseased tomato plants (RT, from eggplant (RB1 and RB2, and pepper (RP and tested on 9 tomato genotypes grown in

  16. Root traits of common bean genotypes used in breeding programs for disease resistance Características de raízes de genótipos de feijão usados em programas de melhoramento para resistência a doenças

    Directory of Open Access Journals (Sweden)

    Rogério Faria Vieira

    2008-06-01

    Full Text Available The objective of this work was to assess root traits of 19 common bean genotypes, used in breeding programs for disease resistance. Genotypes DOR 364 and G 19833 were used as deep and shallow basal root checks, respectively. The number of whorls and basal roots were assessed on five-day old seedlings grown in germination paper. Growth pouch studies were conducted to evaluate basal root gravitropism and lateral root length from primary roots, in seven-day old seedlings. The following root gravitropic traits were estimated: basal growth angle, shallow basal root length (localized in the top 2 cm, and relative shallow basal root growth. Number of whorls varied from 1.47 to 3.07, and number of basal roots ranged from 5.67 (genotype TO to 12.07 (cultivar Jalo MG-65. Cultivars BRS MG Talismã, Carioca, BRS Pioneiro, and Diamante Negro exhibited shallow basal roots, while genotypes Vi-10-2-1, TU, AB 136, and México 54 showed deep basal roots. Cultivar Jalo MG-65 showed more lateral roots from the primary root than the other genotypes. Genotypes used on common bean breeding programs for disease resistance have great variability on basal and primary root traits.O objetivo deste trabalho foi avaliar características de raízes de 19 genótipos de feijão, usados em programas de melhoramento como fontes de resistência a doenças. Os genótipos DOR 364 e G 19833 foram usados como testemunhas de raízes basais superficiais e profundas, respectivamente. O número de verticilos e raízes basais foi avaliado em plântulas com cinco dias de idade que cresceram em papel de germinação. Foram conduzidos estudos em recipientes de crescimento para avaliar o gravitropismo de raízes basais e o comprimento das raízes laterais, na raiz principal de plântulas com sete dias. As seguintes características relacionadas ao gravitropismo das raízes foram avaliadas: ângulo de crescimento de raízes basais, comprimento de raízes basais superficiais (localizadas nos 2

  17. Usefulness of phenotypic and genotypic methods for metallo-beta-lactamases detection in carbapenem-resistant Acinetobacter baumannii strains

    OpenAIRE

    2013-01-01

    Background Acinetobacter baumannii is an opportunistic microorganism with an increasing role in nosocomial outbreaks. For the last 2 decades, a growing number of carbapenem-resistant A. baumannii strains have been identified, including the metallo-beta-lactamases (MBLs) producers. The study aimed to investigate the genetic relatedness of, and MBLs production among, a collection of A. baumannii isolates from Poland. Material/Methods This study involved 78 clinical isolates of carbapenem-resist...

  18. Evaluation of Resistance-Associated Substitutions in NS5A Using Direct Sequence and Cycleave Method and Treatment Outcome with Daclatasvir and Asunaprevir for Chronic Hepatitis C Genotype 1

    Science.gov (United States)

    Ishii, Kunihide; Morita, Masaru; Morita, Yasuyo; Sugiyama, Gen; Fukushima, Hirofumi; Yano, Yoichi; Noguchi, Kazunori; Nakamura, Hiroki; Hisatomi, Junjiro; Kumemura, Hiroto; Shirachi, Miki; Iwane, Shinji; Okada, Michiaki; Honma, Yuichi; Arinaga-Hino, Teruko; Miyajima, Ichiro; Ogata, Kei; Kuwahara, Reiichiro; Amano, Keisuke; Kawaguchi, Toshihiro; Kuromatsu, Ryoko; Torimura, Takuji

    2016-01-01

    Background The aim of this study was to evaluate the efficacy of daclatasvir plus asunaprevir therapy in patients infected with hepatitis C virus and determine its relevance to resistant variants. Methods A total of 629 consecutive patients infected with hepatitis C virus genotype 1 were assessed. Daclatasvir (60 mg/day) plus asunaprevir (200 mg/day) was given for 24 weeks. The virological responses and resistance-associated substitutions of hepatitis C virus mutants were examined by the direct sequence and cycleave methods were evaluated. Results Overall, 89.4% (555/621) of patients exhibited a sustained virological response (SVR). The SVR rates in the patients with wild type, mixed, and mutant type Y93 by direct sequencing were 92.5% (520/562), 70.3% (26/37), and 42.9% (9/21), respectively. The SVR rates in the patients with 100%, 90%, 80%-30%, and 20%-0% Y93 wild by the cycleave method were 93.4% (456/488), 88.2%(30/34), 56.0%(14/25), and 36.8%(7/19), respectively. In contrast, the SVR rates for the wild type and mixed/mutant type L31 by direct sequencing were 90.2% (534/592) and 72.4% (21/29), respectively. In the multivariate analyses, the wild type Y93, no history of simeprevir therapy, the wild type L31, and low HCV RNA level were independent factors of SVR. Conclusion NS5A resistance-associated substitutions, especially Y93H, were major factors predicting the SVR. Although direct sequencing can predict the SVR rate, the cycleave method is considered to be more useful for predicting the SVR when used in combination. PMID:27684567

  19. An Efficient Microarray-Based Genotyping Platform for the Identification of Drug-Resistance Mutations in Majority and Minority Subpopulations of HIV-1 Quasispecies.

    Science.gov (United States)

    Martín, Verónica; Perales, Celia; Fernández-Algar, María; Dos Santos, Helena G; Garrido, Patricia; Pernas, María; Parro, Víctor; Moreno, Miguel; García-Pérez, Javier; Alcamí, José; Torán, José Luis; Abia, David; Domingo, Esteban; Briones, Carlos

    2016-01-01

    The response of human immunodeficiency virus type 1 (HIV-1) quasispecies to antiretroviral therapy is influenced by the ensemble of mutants that composes the evolving population. Low-abundance subpopulations within HIV-1 quasispecies may determine the viral response to the administered drug combinations. However, routine sequencing assays available to clinical laboratories do not recognize HIV-1 minority variants representing less than 25% of the population. Although several alternative and more sensitive genotyping techniques have been developed, including next-generation sequencing (NGS) methods, they are usually very time consuming, expensive and require highly trained personnel, thus becoming unrealistic approaches in daily clinical practice. Here we describe the development and testing of a HIV-1 genotyping DNA microarray that detects and quantifies, in majority and minority viral subpopulations, relevant mutations and amino acid insertions in 42 codons of the pol gene associated with drug- and multidrug-resistance to protease (PR) and reverse transcriptase (RT) inhibitors. A customized bioinformatics protocol has been implemented to analyze the microarray hybridization data by including a new normalization procedure and a stepwise filtering algorithm, which resulted in the highly accurate (96.33%) detection of positive/negative signals. This microarray has been tested with 57 subtype B HIV-1 clinical samples extracted from multi-treated patients, showing an overall identification of 95.53% and 89.24% of the queried PR and RT codons, respectively, and enough sensitivity to detect minority subpopulations representing as low as 5-10% of the total quasispecies. The developed genotyping platform represents an efficient diagnostic and prognostic tool useful to personalize antiviral treatments in clinical practice.

  20. An Efficient Microarray-Based Genotyping Platform for the Identification of Drug-Resistance Mutations in Majority and Minority Subpopulations of HIV-1 Quasispecies

    Science.gov (United States)

    Martín, Verónica; Perales, Celia; Fernández-Algar, María; Dos Santos, Helena G.; Garrido, Patricia; Pernas, María; Parro, Víctor; Moreno, Miguel; García-Pérez, Javier; Alcamí, José; Torán, José Luis; Abia, David; Domingo, Esteban

    2016-01-01

    The response of human immunodeficiency virus type 1 (HIV-1) quasispecies to antiretroviral therapy is influenced by the ensemble of mutants that composes the evolving population. Low-abundance subpopulations within HIV-1 quasispecies may determine the viral response to the administered drug combinations. However, routine sequencing assays available to clinical laboratories do not recognize HIV-1 minority variants representing less than 25% of the population. Although several alternative and more sensitive genotyping techniques have been developed, including next-generation sequencing (NGS) methods, they are usually very time consuming, expensive and require highly trained personnel, thus becoming unrealistic approaches in daily clinical practice. Here we describe the development and testing of a HIV-1 genotyping DNA microarray that detects and quantifies, in majority and minority viral subpopulations, relevant mutations and amino acid insertions in 42 codons of the pol gene associated with drug- and multidrug-resistance to protease (PR) and reverse transcriptase (RT) inhibitors. A customized bioinformatics protocol has been implemented to analyze the microarray hybridization data by including a new normalization procedure and a stepwise filtering algorithm, which resulted in the highly accurate (96.33%) detection of positive/negative signals. This microarray has been tested with 57 subtype B HIV-1 clinical samples extracted from multi-treated patients, showing an overall identification of 95.53% and 89.24% of the queried PR and RT codons, respectively, and enough sensitivity to detect minority subpopulations representing as low as 5–10% of the total quasispecies. The developed genotyping platform represents an efficient diagnostic and prognostic tool useful to personalize antiviral treatments in clinical practice. PMID:27959928

  1. Salt resistance of different tomato genotypes at seed germination stage%不同基因型番茄种子萌发期的耐盐性

    Institute of Scientific and Technical Information of China (English)

    杨凤军; 李天来; 臧忠婧; 宿越; 鲁少尉

    2009-01-01

    Based on the cluster analysis of relative germination potential and relative germination rate under NaCl stress, fourteen tomato genotypes were clustered into two groups. Five tomato genotypes held high resistance to NaCl stress, and nine tomato genotypes were moderately NaCl- tolerant. The highly NaCl-tolerant genotypes wild Lycopersicon pimpinellifolium, Liaoyuanhongmanao and Hongbaoshi and the moderately NaCl- tolerant genotype Liaoyuanhongduoli were then under different Na+-salts and NaCl, Na+, and Cl- stresses. The responses of the four tomato genotypes to different Na+-salts stress were the same as those to NaCl stress. Among the test Na+-salts, NaHCO3 had the greatest impact. Under the stress of 100 mmol NaHCO3·L-1, the embryo's relative lengths of the four tomato genotypes were all below 8 %. The inhibitory effect of test Na+-salts on tomato seed germination was in the order of NaNO3

  2. Comparison of Xpert MTB/RIF Assay and GenoType MTBDRplus DNA Probes for Detection of Mutations Associated with Rifampicin Resistance in Mycobacterium tuberculosis.

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    Arfatur Rahman

    Full Text Available GeneXpert MTB/RIF (Xpert and Genotype MTBDRplus (DRplus are two World Health Organization (WHO endorsed probe based molecular drug susceptibility testing (DST methods for rapid diagnosis of drug resistant tuberculosis. Both methods target the same 81 bp Rifampicin Resistance Determining Region (RRDR of bacterial RNA polymerase β subunit (rpoB for detection of Rifampicin (RIF resistance associated mutations using DNA probes. So there is a correspondence of the probes of each other and expected similarity of probe binding.We analyzed 92 sputum specimens by Xpert, DRplus and LJ proportion method (LJ-DST. We compared molecular DSTs with gold standard LJ-DST. We wanted to see the agreement level of two molecular methods for detection of RIF resistance associated mutations. The 81bp RRDR region of rpoB gene of discrepant cases between the two molecular methods was sequenced by Sanger sequencing.The agreement of Xpert and DRplus with LJ-DST for detection of RIF susceptibility was found to be 93.5% and 92.4%, respectively. We also found 92.4% overall agreement of two molecular methods for the detection of RIF susceptibility. A total of 84 out of 92 samples (91.3% had agreement on the molecular locus of RRDR mutation by DRplus and Xpert. Sanger sequencing of 81bp RRDR revealed that Xpert probes detected seven of eight discrepant cases correctly and DRplus was erroneous in all the eight cases.Although the overall concordance with LJ-DST was similar for both Xpert and DRplus assay, Xpert demonstrated more accuracy in the detection of RIF susceptibility for discrepant isolates compared with DRplus. This observation would be helpful for the improvement of probe based detection of drug resistance associated mutations especially rpoB mutation in M. tuberculosis.

  3. Detection of multi-drug resistance & characterization of mutations in Mycobacterium tuberculosis isolates from North- Eastern States of India using GenoType MTBDRplus assay

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    Ritu Singhal

    2014-01-01

    Full Text Available Background & objectives: Information on drug resistance tuberculosis is sparse from North-East (N-E States of India. We undertook this study to detect multi-drug resistant tuberculosis (MDR-TB among MDR-TB suspects, and common mutations among MDR-TB cases using GenoType MTBDRplus. Methods: All MDR suspect patients deposited sputum samples to peripheral designated microscopy centres (DMC in North-East States. The district TB officers (DTOs facilitated the transport of samples collected during January 2012 to August 2012 to our laboratory. The line probe assay to detect common mutations in the rpoB gene for rifampicin (RIF and katG and inhA genes for isoniazid (INH, respectively was performed on 339 samples or cultures. Results: A total of 553 sputum samples from MDR suspects were received of which, 181 (32.7% isolates were found to be multi-drug resistant. Missing WT8 along with mutation in codon S531L was commonest pattern for rifampicin resistant isolates (65.1% and missing WT along with mutations in codon S315T1 of katG gene was commonest pattern for isoniazid resistant isolates (86.2%. Average turn-around time for dispatch of LPA result to these States from cultures and samples was 23.4 and 5.2 days, respectively. Interpretations & conclusions: The MDR-TB among MDR-TB suspects in North-Eastern States of India was found to be 32.7 per cent. The common mutations obtained for RIF and INH in the region were mostly similar to those reported earlier.

  4. Antimicrobial Resistance Profile and Genotypic Characteristics of Streptococcus suis Capsular Type 2 Isolated from Clinical Carrier Sows and Diseased Pigs in China

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    Chunping Zhang

    2015-01-01

    Full Text Available Streptococcus suis serotype 2 is an important zoonotic pathogen. Antimicrobial resistance phenotypes and genotypic characterizations of S. suis 2 from carrier sows and diseased pigs remain largely unknown. In this study, 96 swine S. suis type 2, 62 from healthy sows and 34 from diseased pigs, were analyzed. High frequency of tetracycline resistance was observed, followed by sulfonamides. The lowest resistance of S. suis 2 for β-lactams supports their use as the primary antibiotics to treat the infection of serotype 2. In contrast, 35 of 37 S. suis 2 with MLSB phenotypes were isolated from healthy sows, mostly encoded by the ermB and/or the mefA genes. Significantly lower frequency of mrp+/epf+/sly+ was observed among serotype 2 from healthy sows compared to those from diseased pigs. Furthermore, isolates from diseased pigs showed more homogeneously genetic patterns, with most of them clustered in pulsotypes A and E. The data indicate the genetic complexity of S. suis 2 between herds and a close linkage among isolates from healthy sows and diseased pigs. Moreover, many factors, such as extensive use of tetracycline or diffusion of Tn916 with tetM, might have favored for the pathogenicity and widespread dissemination of S. suis serotype 2.

  5. Pre-existence and Persistence of Resistant Minority Hepatitis C Virus Variants in Genotype 1-Infected Patients Treated With Simeprevir/Peginterferon/Ribavirin.

    Science.gov (United States)

    Fevery, Bart; Thys, Kim; Van Eygen, Veerle; Verbinnen, Thierry; Van Rossem, Elizabeth; Buelens, Annemie; Aerssens, Jeroen; Witek, James; Picchio, Gaston; De Meyer, Sandra; Lenz, Oliver

    2016-03-01

    Background.  The pre-existence of minority hepatitis C virus (HCV) variants and their impact on treatment outcome, as well as the persistence of emerging resistant variants posttreatment in patients failing treatment with simeprevir/peginterferon/ribavirin (SMV/PR), were assessed by deep sequencing (DS). Methods.  Population sequencing (PS) and Illumina DS were performed on HCV genotype 1 isolates from patients treated with SMV/PR in Phase 2b (PILLAR [NCT00882908] and ASPIRE [NCT00980330]) and Phase 3 (QUEST-1 [NCT01289782], QUEST-2 [NCT01290679], and PROMISE [NCT01281839]) trials. Results.  Minority polymorphisms (ie, detected pretreatment by DS only) reducing SMV activity in vitro were uncommon (3.6%, 19 of 534 patients). These SMV-resistant minority polymorphisms were detected in similar proportions of patients achieving (3.7%) and not achieving (3.3%) sustained virologic response with SMV/PR and generally did not emerge as major variants at time of failure. SMV-resistant variants emerging at time of failure were no longer detected at end of study in 69.3% and 52.0% of the patients by PS and DS, respectively. Conclusions.  Minority polymorphisms did not impact outcome of SMV/PR treatment. The majority of emerging variants that became undetectable at end of study by PS were also undetectable by DS. These results suggest no added value of DS for clinical usage of SMV.

  6. Molecular epidemiological survey on quinolone resistance genotype and phenotype of Escherichia coli in septicemic broilers in Hebei, China.

    Science.gov (United States)

    Xie, Rong; Huo, Shuying; Li, Yurong; Chen, Ligong; Zhang, Feiyan; Wu, Xianjun

    2014-02-01

    In this study, the quinolone-resistant determining region (QRDR) of gyrA of Escherichia coli and plasmid-mediated quinolone resistance (PMQR) genes, qnr(qnrA, qnrB, and qnrS), and aac(6 ')-Ib-cr were detected, sequenced, and analyzed. In addition, antimicrobial susceptibility tests (using the Kirby-Bauer disc diffusion method) were performed for all 111 E. coli isolates from septicemic broilers in Hebei, China. The results show that the resistance rates were as follows: ofloxacin 99.10%, ciprofloxacin 93.69%, levofloxacin 91.89%, norfloxacin 90.09%, and gatifloxacin 76.58%. Of the PMQR genes examined, aac(6 ')-Ib-cr (36.04%) was the most frequently identified gene in all isolates, followed by qnrS (8.11%), qnrB (0.90%), and qnrA (0%). Of the QRDR examined in the 40 phenotypic quinolone-resistant isolates, compared with the gyrA(+) gene of E. coli K-12, 4 amino acid exchanges were found, namely Ser-83→Asp, Asp-87→Asn, Asp-87→Tyr, and Asp-87→Ala, and all 40 isolates had 1 or 2 exchanges in QRDR. It was concluded that quinolone-resistance in E. coli remains a serious problem in Hebei, China. Therefore, there is considerable local surveillance of quinolone resistance. Plasmid-mediated quinolone resistance of the qnr type remains rare in Hebei, China, and mutation in QRDR may be the main problem.

  7. Genotypic and phenotypic characterization of the thymidine kinase of ACV-resistant HSV-1 derived from an acyclovir-sensitive herpes simplex virus type 1 strain.

    Science.gov (United States)

    Saijo, Masayuki; Suzutani, Tatsuo; De Clercq, Erik; Niikura, Masahiro; Maeda, Akihiko; Morikawa, Shigeru; Kurane, Ichiro

    2002-12-01

    Twenty-four strains of acyclovir (ACV)-resistant (ACV(r)) herpes simplex virus type 1 (HSV-1) were generated from the HSV-1 TAS strain by exposure to ACV, and the genotype and phenotype of the thymidine kinase (TK) from these mutants were analyzed. The TK polypeptide of the ACV(r) HSV-1 strains was examined by Western blot using an anti-HSV-1 TK rabbit serum. The sensitivity of each strain to ACV, foscarnet and cidofovir (CDV) was also determined. A single guanine (G) insertion or a single cytosine (C) deletion was detected in 12 of the 24 ACV(r) strains at the G or C homopolymer stretches within the TK gene. Genotypic analysis predicted that two thirds of the ACV(r) HSV-1 strains expressed truncated TK polypeptides, while one third expressed viral TK polypeptide with a single amino acid substitution at various sites. Western blot abnormalities in the viral TK polypeptides were identified in 21 ACV(r) strains. There was an inverse correlation between the susceptibility of the HSV-1 mutant strains to ACV and that to CDV. Nucleotide sequencing of the TK gene and Western blot analysis of the viral TK polypeptides are considered to be one of the methods for predicting virus sensitivity to ACV and CDV.

  8. Cost-Effectiveness and Efficacy of spa, SCCmec, and PVL Genotyping of Methicillin-Resistant Staphylococcus aureus as Compared to Pulsed-Field Gel Electrophoresis

    Science.gov (United States)

    Li, Vincent; Chui, Linda; Louie, Lisa; Simor, Andrew; Golding, George R.; Louie, Marie

    2013-01-01

    Pulsed-field gel electrophoresis (PFGE) is a valuable molecular typing assay used for methicillin-resistant Staphylococcus aureus (MRSA) surveillance and genotyping. However, there are several limitations associated with PFGE. In Alberta, Canada, the significant increase in the number of MRSA isolates submitted to the Provincial Laboratory for Public Health (ProvLab) for PFGE typing led to the need for an alternative genotyping method. In this study, we describe the transition from PFGE to Staphylococcus protein A (spa), Staphylococcal cassette chromosome (SCCmec), and Panton-Valentine leukocidin (PVL) typing. A total of 1915 clinical MRSA isolates collected from 2005 to 2009 were used to develop and validate an algorithm for assigning PFGE epidemic types using spa, SCCmec, and PVL typing and the resulting data was used to populate a new Alberta MRSA typing database. An additional 12620 clinical MRSA isolates collected from 2010 to 2012 as part of ongoing routine molecular testing at ProvLab were characterized using the new typing algorithm and the Alberta MRSA typing database. Switching to spa, SCCmec, and PVL from PFGE typing substantially reduced hands-on and turn-around times while maintaining historical PFGE epidemic type designations. This led to an approximate $77,000 reduction in costs from 2010 to 2012. PFGE typing is still required for a small subset of MRSA isolates that have spa types that are rare, novel, or associated with more than one PFGE epidemic type. PMID:24244440

  9. Influence of genotype and processing on the in vitro rate of starch hydrolysis and resistant starch formation in peas (Pisum sativum L.).

    Science.gov (United States)

    Skrabanja, V; Liljeberg, H G; Hedley, C L; Kreft, I; Björck, I M

    1999-05-01

    The formation of resistant starch (RS) and the rate of starch hydrolysis were evaluated in vitro in a wild type of green-seeded pea genotype RRRbRb BC3 (33-Am) with 32.7% amylose content and in two mutants RRrbrb BC3 (23-Am) and rrRbRb BC3 (65-Am) with amylose contents of 23.3 and 65.1%, respectively. Pea samples were intact or homogenized and subjected either to autoclaving or to boiling at atmospheric pressure. The amount of RS (total starch basis) varied from 6.2 to 12.9% in the 23-Am products and from 31.2 to 33.4% in the 65-Am products. The RS level of the 33-Am product with a regular amylose content was 11.0%. Both the 23-Am and the 65-Am products were abundant sources of dietary fiber (39 and 34%, dry matter basis, respectively) versus 23% in the regular pea product. The amylose/amylopectin ratio was an important determinant of the rate of starch hydrolysis. The hydrolysis indices (HI) and predicted glycemic indices were lowest in the 65-Am peas (HI range = 42-59) as compared to the 23-Am peas (HI range = 53-84). It is concluded that the pea genotypes covered a wide range in starch availability, which is likely to affect nutritional parameters such as glycemic responses and colonic delivery of starch.

  10. Pseudo-outbreak of pre-extensively drug-resistant (Pre-XDR) tuberculosis in Kinshasa: collateral damage caused by false detection of fluoroquinolone resistance by GenoType MTBDRsl.

    Science.gov (United States)

    Kaswa, Michel K; Aloni, Muriel; Nkuku, Léontine; Bakoko, Brian; Lebeke, Rossin; Nzita, Albert; Muyembe, Jean Jacques; de Jong, Bouke C; de Rijk, Pim; Verhaegen, Jan; Boelaert, Marleen; Ieven, Margareta; Van Deun, Armand

    2014-08-01

    Fluoroquinolones are the core drugs for the management of multidrug-resistant tuberculosis (MDR-TB). Molecular drug susceptibility testing methods provide considerable advantages for scaling up programmatic management and surveillance of drug-resistant TB. We describe here the misidentification of fluoroquinolone resistance by the GenoType MTBDRsl (MTBDRsl) (Hain Lifescience GmbH, Nehren, Germany) line probe assay (LPA) encountered during a feasibility and validation study for the introduction of this rapid drug susceptibility test in Kinshasa, Democratic Republic of Congo. The double gyrA mutation 80Ala and 90Gly represented 57% of all fluoroquinolone mutations identified from MDR-TB patient sputum samples, as confirmed by DNA sequencing. This double mutation was previously found to be associated with susceptibility to fluoroquinolones, yet it leads to absent hybridization of a wild-type band in the MTBDRsl and is thus falsely scored as resistance. Our findings suggest that MTBDRsl results must be interpreted with caution when the interpretation is based solely on the absence of a wild-type band without confirmation by visualization of a mutant band. Performance of the MTBDRsl LPA might be improved by replacing the gyrA wild-type probes by additional probes specific for well-documented gyrA mutations that confer clinically relevant resistance.

  11. Insecticide resistance mechanisms in the green peach aphid Myzus persicae (Hemiptera: Aphididae I: A transcriptomic survey.

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    Andrea X Silva

    Full Text Available BACKGROUND: Insecticide resistance is one of the best examples of rapid micro-evolution found in nature. Since the development of the first synthetic insecticide in 1939, humans have invested considerable effort to stay ahead of resistance phenotypes that repeatedly develop in insects. Aphids are a group of insects that have become global pests in agriculture and frequently exhibit insecticide resistance. The green peach aphid, Myzus persicae, has developed resistance to at least seventy different synthetic compounds, and different insecticide resistance mechanisms have been reported worldwide. METHODOLOGY/PRINCIPAL FINDINGS: To further characterize this resistance, we analyzed genome-wide transcriptional responses in three genotypes of M. persicae, each exhibiting different resistance mechanisms, in response to an anti-cholinesterase insecticide. The sensitive genotype (exhibiting no resistance mechanism responded to the insecticide by up-regulating 183 genes primarily ones related to energy metabolism, detoxifying enzymes, proteins of extracellular transport, peptidases and cuticular proteins. The second genotype (resistant through a kdr sodium channel mutation, up-regulated 17 genes coding for detoxifying enzymes, peptidase and cuticular proteins. Finally, a multiply resistant genotype (carrying kdr and a modified acetylcholinesterase, up-regulated only 7 genes, appears not to require induced insecticide detoxification, and instead down-regulated many genes. CONCLUSIONS/SIGNIFICANCE: This study suggests strongly that insecticide resistance in M. persicae is more complex that has been described, with the participation of a broad array of resistance mechanisms. The sensitive genotype exhibited the highest transcriptional plasticity, accounting for the wide range of potential adaptations to insecticides that this species can evolve. In contrast, the multiply resistant genotype exhibited a low transcriptional plasticity, even for the expression

  12. Phenotypic and genotypic characteristics of methicillin/oxacillin-resistant Staphylococcus intermedius isolated from clinical specimens during routine veterinary microbiological examinations.

    Science.gov (United States)

    Zubeir, I E M El; Kanbar, T; Alber, J; Lämmler, C; Akineden, O; Weiss, R; Zschöck, M

    2007-03-31

    Methicillin/oxacillin resistance of 10 S. intermedius strains was investigated by conventional and molecular methods. The strains tested had been isolated in Germany during routine veterinary microbiological examinations of specimens from a small animal clinic between May and September 2005. Epidemiological relationships of the strains were studied by macrorestriction analysis of their chromosomal DNA using pulsed field gel electrophoresis (PFGE). Species identity of the 10 S. intermedius strains was confirmed by conventional methods and by PCR mediated amplification of S. intermedius specific segments of thermonuclease encoding gene nuc. As controls, four methicillin/oxacillin resistant S. intermedius (MRSI) strains obtained from specimens sent by four veterinarians and three selected methicillin/oxacillin sensitive S. intermedius (MSSI), also obtained from the small animal clinic, were tested. The 10 strains, representing approximately 6% of all S. intermedius isolated from the clinic throughout the time period mentioned above, and the four MRSI obtained from veterinarians, were methicillin/oxacillin and penicillin resistant using disk diffusion tests and could be cultivated on oxacillin resistant screening agar base (ORSAB). Both resistances could be confirmed by multiplex PCR detecting the resistance genes mecA and blaZ. The three MSSI were methicillin/oxacillin sensitive in all tests. Epidemiological investigation by macrorestriction analysis of the chromosomal DNA of the strains by pulsed field gel electrophoresis revealed that all 10 MRSI strains obtained from the clinic and the four MRSI strains obtained from veterinarians, in contrast to the three MSSI strains, represent identical or closely related bacterial clones possibly indicating a cross-infection of the animals in the clinic and the distribution of a single MRSI clone in the pet population.

  13. Comparison of Ahlstrom grade 226, Munktell TFN, and Whatman 903 filter papers for dried blood spot specimen collection and subsequent HIV-1 load and drug resistance genotyping analysis.

    Science.gov (United States)

    Rottinghaus, Erin; Bile, Ebi; Modukanele, Mosetsanagape; Maruping, Maruping; Mine, Madisa; Nkengasong, John; Yang, Chunfu

    2013-01-01

    Dried blood spots (DBS) collected onto filter paper have eased the difficulty of blood collection in resource-limited settings. Currently, Whatman 903 (W-903) filter paper is the only filter paper that has been used for HIV load and HIV drug resistance (HIVDR) testing. We therefore evaluated two additional commercially available filter papers, Ahlstrom grade 226 (A-226) and Munktell TFN (M-TFN), for viral load (VL) testing and HIVDR genotyping using W-903 filter paper as a comparison group. DBS specimens were generated from 344 adult patients on antiretroviral therapy (ART) in Botswana. The VL was measured with NucliSENS EasyQ HIV-1 v2.0, and genotyping was performed for those specimens with a detectable VL (≥ 2.90 log(10) copies/ml) using an in-house method. Bland-Altman analysis revealed a strong concordance in quantitative VL analysis between W-903 and A-226 (bias = -0.034 ± 0.246 log(10) copies/ml [mean difference ± standard deviation]) and W-903 and M-TFN (bias = -0.028 ± 0.186 log(10) copies/ml) filter papers, while qualitative VL analysis for virological failure determination, defined as a VL of ≥ 3.00 log(10) copies/ml, showed low sensitivities for A-266 (71.54%) and M-TFN (65.71%) filter papers compared to W-903 filter paper. DBS collected on M-TFN filter paper had the highest genotyping efficiency (100%) compared to W-903 and A-226 filter papers (91.7%) and appeared more sensitive in detecting major HIVDR mutations. DBS collected on A-226 and M-TFN filter papers performed similarly to DBS collected on W-903 filter paper for quantitative VL analysis and HIVDR detection. Together, the encouraging genotyping results and the