scholarly journals Fusidic Acid Resistance Rates and Prevalence of Resistance Mechanisms among Staphylococcus spp. Isolated in North America and Australia, 2007-2008

2010 ◽  
Vol 54 (9) ◽  
pp. 3614-3617 ◽  
Author(s):  
Mariana Castanheira ◽  
Amy A. Watters ◽  
Jan M. Bell ◽  
John D. Turnidge ◽  
Ronald N. Jones
Keyword(s):  
United States ◽  
Resistance Genes ◽  
Fusidic Acid ◽  
Dominant Role ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Acid Resistance ◽  
The United States ◽  
Resistance Mechanisms ◽  
Resistance Rates

ABSTRACT Among 4,167 Staphylococcus aureus and 790 coagulase-negative Staphylococcus (CoNS; not S. saprophyticus) isolates collected consecutively from North American and Australian hospitals, only 87 (1.7% overall) isolates displayed a fusidic acid (FA; also known as CEM-102) MIC of ≥2 μg/ml (FA resistance). These strains were further evaluated with a multiplex PCR to amplify the acquired resistance genes fusB, fusC, and fusD. Mutations in fusA and fusE were evaluated in all isolates showing an absence of acquired resistance genes and/or showing FA MIC values of ≥64 μg/ml. S. aureus resistance rates were very low in the United States (0.3%) and were higher in Canada and Australia (7.0% for both countries). Among CoNS isolates, FA resistance rates were significantly more elevated than that for S. aureus (7.2 to 20.0%; the highest rates were in Canada). All 52 (41 CoNS) FA-resistant isolates from the United States showed FA MIC results of ≤64 μg/ml, and 7 of 11 S. aureus isolates carried fusC. CoNS strains from the United States carried fusB or fusC. In Canada, fusB and fusC occurrences were similar among S. aureus and CoNS isolates, and modestly elevated FA MIC values were observed (all MIC results were ≤32 μg/ml). Isolates from Australia showed MIC values ranging from 2 to 32 μg/ml, and S. aureus isolates were predominantly fusC positive. fusA mutations were detected in only three S. aureus isolates, conferring FA MIC values of 2 to 8 μg/ml. Target mutations have been considered the primary FA resistance mechanism among Staphylococcus spp.; however, acquired resistance genes appear to have a dominant role in resistance against this older antimicrobial agent. In summary, this study shows that acquired genes are highly prevalent among FA-resistant strains (>90%) in three nations with distinct or absence (United States) of fusidic acid clinical use.

scholarly journals Antimicrobial Susceptibility and Clonality of Clinical Ureaplasma Isolates in the United States

2016 ◽  
Vol 60 (8) ◽  
pp. 4793-4798 ◽  
Author(s):  
Javier Fernández ◽  
Melissa J. Karau ◽  
Scott A. Cunningham ◽  
Kerryl E. Greenwood-Quaintance ◽  
Robin Patel
Keyword(s):  
United States ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Ureaplasma Urealyticum ◽  
Resistance Mechanism ◽  
The United States ◽  
Resistance Mechanisms ◽  
Resistant Isolate ◽  
Limited Information ◽  
Content Type

ABSTRACTUreaplasma urealyticumandUreaplasma parvumare pathogens involved in urogenital tract and intrauterine infections and also in systemic diseases in newborns and immunosuppressed patients. There is limited information on the antimicrobial susceptibility and clonality of these species. In this study, we report the susceptibility of 250 contemporary isolates ofUreaplasma(202U. parvumand 48U. urealyticumisolates) recovered at Mayo Clinic, Rochester, MN. MICs of doxycycline, azithromycin, ciprofloxacin, tetracycline, erythromycin, and levofloxacin were determined by broth microdilution, with MICS of the last three interpreted according to CLSI guidelines. Levofloxacin resistance was found in 6.4% and 5.2% ofU. parvumandU. urealyticumisolates, respectively, while 27.2% and 68.8% of isolates, respectively, showed ciprofloxacin MICs of ≥4 μg/ml. The resistance mechanism of levofloxacin-resistant isolates was due to mutations inparC, with the Ser83Leu substitution being most frequent, followed by Glu87Lys. No macrolide resistance was found among the 250 isolates studied; a singleU. parvumisolate was tetracycline resistant.tet(M) was found in 10U. parvumisolates, including the single tetracycline-resistant isolate, as well as in 9 isolates which had low tetracycline and doxycycline MICs. Multilocus sequence typing (MLST) performed on a selection of 46 isolates showed high diversity within the clinicalUreaplasmaisolates studied, regardless of antimicrobial susceptibility. The present work extends previous knowledge regarding susceptibility to antimicrobial agents, resistance mechanisms, and clonality ofUreaplasmaspecies in the United States.

scholarly journals Multicenter Study of Isavuconazole MIC Distributions and Epidemiological Cutoff Values for Aspergillus spp. for the CLSI M38-A2 Broth Microdilution Method

2013 ◽  
Vol 57 (8) ◽  
pp. 3823-3828 ◽  
Author(s):  
A. Espinel-Ingroff ◽  
A. Chowdhary ◽  
G. M. Gonzalez ◽  
C. Lass-Flörl ◽  
E. Martin-Mazuelos ◽  
...  
Keyword(s):  
Species Complex ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
The United States ◽  
Resistance Mechanisms ◽  
Broth Microdilution ◽  
Content Type ◽  
Microdilution Method ◽  
Cutoff Values ◽  
Broth Microdilution Method

ABSTRACTEpidemiological cutoff values (ECVs) were established for the new triazole isavuconazole andAspergillusspecies wild-type (WT) MIC distributions (organisms in a species-drug combination with no detectable acquired resistance mechanisms) that were defined with 855Aspergillus fumigatus, 444A. flavus, 106A. nidulans, 207A. niger, 384A. terreus, and 75A. versicolorspecies complex isolates; 22AspergillussectionUstiisolates were also included. CLSI broth microdilution MIC data gathered in Europe, India, Mexico, and the United States were aggregated to statistically define ECVs. ECVs were 1 μg/ml for theA. fumigatusspecies complex, 1 μg/ml for theA. flavusspecies complex, 0.25 μg/ml for theA. nidulansspecies complex, 4 μg/ml for theA. nigerspecies complex, 1 μg/ml for theA. terreusspecies complex, and 1 μg/ml for theA. versicolorspecies complex; due to the small number of isolates, an ECV was not proposed forAspergillussectionUsti. These ECVs may aid in detecting non-WT isolates with reduced susceptibility to isavuconazole due tocyp51A(anA. fumigatusspecies complex resistance mechanism among the triazoles) or other mutations.

scholarly journals Pathogenic Variation of Phakopsora pachyrhizi Isolates on Soybean in the United States from 2006 to 2009

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 75-81 ◽  
Author(s):  
M. Twizeyimana ◽  
G. L. Hartman
Keyword(s):  
United States ◽  
Resistance Genes ◽  
The United States ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Soybean Genotype ◽  
Pathogenic Variation ◽  
Differential Set ◽  
Soybean Genotypes ◽  
Soybean Leaves

The introduction of Phakopsora pachyrhizi, the cause of soybean rust, into the United States is a classic case of a pathogen introduction that became established in a new geographical region overwintering on a perennial host (kudzu, Pueraria lobata). The objective of our study was to classify the pathogenic variation of P. pachyrhizi isolates collected in the United States, and to determine the spatial and temporal associations. In total, 72 isolates of P. pachyrhizi collected from infected kudzu and soybean leaves in the United States were purified, then established and increased on detached soybean leaves. These isolates were tested for virulence and aggressiveness on a differential set of soybean genotypes that included six genotypes with known resistance genes (Rpp), one resistant genotype without any known characterized resistance gene, and a susceptible genotype. Three pathotypes were identified among the 72 U.S. P. pachyrhizi isolates based on the virulence of these isolates on the genotypes in the differential set. Six aggressiveness groups were established based on sporulating-uredinia production recorded for each isolate on each soybean genotype. All three pathotypes and all six aggressiveness groups were found in isolates collected from the southern region and from both hosts (kudzu or soybean) in 2008. Shannon's index based on the number of pathotypes indicated that isolates from the South region were more diverse (H = 0.83) compared with the isolates collected in other regions. This study establishes a baseline of pathogenic variation of P. pachyrhizi in the United States that can be further compared with variation reported in other regions of the world and in future studies that monitor P. pachyrhizi virulence in association to deployment of rust resistance genes.

scholarly journals The United States, Britain and the Marshall Plan: oil and finance in the early postwar era*

2018 ◽  
Vol 27 (1) ◽  
pp. 355-373
Author(s):  
Nicholas Miller Trebat
Keyword(s):  
United States ◽  
World War Ii ◽  
Middle East ◽  
Positive Impact ◽  
Dominant Role ◽  
Oil Industry ◽  
The United States ◽  
Primary Objective ◽  
Marshall Plan ◽  
Foreign Economic Policy

Abstract This paper discusses United States foreign economic policy in the early post-World War II period, focusing on Anglo-American relations and the international oil industry. Contrary to popular opinion, these relations were not friendly, as one of the goals of US policymakers was to force the former power to relinquish key areas of strategic and commercial influence, such as the trading networks of the British Commonwealth and, more importantly, the oil regions of the Middle East. In particular, the paper analyzes US oil policy during the Marshall Plan. Though not questioning the Plan’s overall positive impact on European economic growth, the paper argues that, with regard to the oil industry, its primary objective was not to stimulate recovery but to secure a dominant role for US producers in the Middle East.

scholarly journals Summary of Linezolid Activity and Resistance Mechanisms Detected during the 2012 LEADER Surveillance Program for the United States

2013 ◽  
Vol 58 (2) ◽  
pp. 1243-1247 ◽  
Author(s):  
Rodrigo E. Mendes ◽  
Robert K. Flamm ◽  
Patricia A. Hogan ◽  
James E. Ross ◽  
Ronald N. Jones
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Susceptibility Testing ◽  
The United States ◽  
Resistance Mechanisms ◽  
Regulatory Approval ◽  
Surveillance Program ◽  
Gram Positive ◽  
Content Type

ABSTRACTThis study summarizes the linezolid susceptibility testing results for 7,429 Gram-positive pathogens from 60 U.S. sites collected during the 2012 sampling year for the LEADER Program. Linezolid showed potent activity when tested against 2,980Staphylococcus aureusisolates, inhibiting all but 3 at ≤2 μg/ml. Similarly, linezolid showed coverage against 99.5% of enterococci, as well as for all streptococci tested. These results confirm a long record of linezolid activity against U.S. Gram-positive isolates since regulatory approval in 2000.

scholarly journals Distribution and Characterization of Podosphaera macularis Virulent on Hop Cultivars Possessing R6-Based Resistance to Powdery Mildew

Plant Disease ◽  
2016 ◽  
Vol 100 (6) ◽  
pp. 1212-1221 ◽  
Author(s):  
Sierra N. Wolfenbarger ◽  
Stephen T. Massie ◽  
Cynthia Ocamb ◽  
Emily B. Eck ◽  
Gary G. Grove ◽  
...  
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Mating Type ◽  
Resistance Genes ◽  
Severe Disease ◽  
The United States ◽  
Fitness Cost ◽  
Eastern United States ◽  
Host Genotype ◽  
Podosphaera Macularis

Host resistance, both quantitative and qualitative, is the preferred long-term approach for disease management in many pathosystems, including powdery mildew of hop (Podosphaera macularis). In 2012, an epidemic of powdery mildew occurred in Washington and Idaho on previously resistant cultivars whose resistance was putatively based on the gene designated R6. In 2013, isolates capable of causing severe disease on cultivars with R6-based resistance were confirmed in Oregon and became widespread during 2014. Surveys of commercial hop yards during 2012 to 2014 documented that powdery mildew is now widespread on cultivars possessing R6 resistance in Washington and Oregon, and the incidence of disease is progressively increasing. Pathogenic fitness, race, and mating type of R6-virulent isolates were compared with isolates of P. macularis lacking R6 virulence. All isolates were positive for the mating type idiomorph MAT1-1 and were able to overcome resistance genes Rb, R3, and R5 but not R1 or R2. In addition, R6-virulent isolates were shown to infect differential cultivars reported to possess the R6 gene and also the R4 gene, although R4 has not yet been broadly deployed in the United States. R6-virulent isolates were not detected from the eastern United States during 2012 to 2015. In growth chamber studies, R6-virulent isolates of P. macularis had a significantly longer latent period and produced fewer lesions on plants with R6 as compared with plants lacking R6, indicating a fitness cost to the fungus. R6-virulent isolates also produced fewer conidia when compared with isolates lacking R6 virulence, independent of whether the isolates were grown on a plant with or without R6. Thus, it is possible that the fitness cost of R6 virulence occurs regardless of host genotype. In field studies, powdery mildew was suppressed by at least 50% on plants possessing R6 as compared with those without R6 when coinoculated with R6-virulent and avirulent isolates. R6 virulence in P. macularis appears to be race specific and, at this time, imposes a measurable fitness penalty on the fungus. Resistance genes R1 and R2 appear to remain effective against R6-virulent isolates of P. macularis in the U.S. Pacific Northwest.

Multimodel Estimates of Atmospheric Response to Modes of SST Variability and Implications for Droughts

2010 ◽  
Vol 23 (16) ◽  
pp. 4327-4341 ◽  
Author(s):  
Philip J. Pegion ◽  
Arun Kumar
Keyword(s):  
United States ◽  
Climate Variability ◽  
General Circulation ◽  
Dominant Role ◽  
Circulation Model ◽  
The United States ◽  
Precipitation Variability ◽  
Climate Extreme ◽  
Central Pacific ◽  
Sst Variability

Abstract A set of idealized global model experiments was performed by several modeling centers as part of the Drought Working Group of the U.S. Climate Variability and Predictability component of the World Climate Research Programme (CLIVAR). The purpose of the experiments was to assess the role of the leading modes of sea surface temperature (SST) variability on the climate over the continents, with particular emphasis on the influence of SSTs on surface climate variability and droughts over the United States. An analysis based on several models gives more creditability to the results since it relies on the assessment of impacts that are robust across different models. Coordinated atmospheric general circulation model (AGCM) simulations forced with three modes of SST variability were analyzed. The results show that the SST-forced precipitation variability over the central United States is dominated by the SST mode with maximum loading in the central Pacific Ocean. The SST mode with loading in the Atlantic Ocean, and a mode that is dominated by trends in SSTs, lead to a smaller response. Based on the response to the idealized SSTs, the precipitation response for the twentieth century was also reconstructed. A comparison with the Atmospheric Model Intercomparison Project (AMIP) simulations forced with the observed SSTs illustrates that the reconstructed precipitation variability was similar to the one in the AMIP simulations, further supporting the conclusion that the SST modes identified in the present analysis play a dominant role in the precipitation variability over the United States. One notable exception is the Dust Bowl of the 1930s, and further analysis regarding this major climate extreme is discussed.

Chandler and Business History in Japan

2008 ◽  
Vol 82 (2) ◽  
pp. 301-308 ◽  
Author(s):  
Marie Anchordoguy
Keyword(s):  
United States ◽  
Industrial Development ◽  
Raw Materials ◽  
Dominant Role ◽  
The United States ◽  
Business History ◽  
Large Firms ◽  
Capitalist System ◽  
Visible Hand ◽  
Chain Of Command

The work and ideas of Alfred D.Chandler Jr. have enriched the field of Japanese business history and our understanding of that nation's industrial development. Chandler's studies about the rise of the large, professionally managed, multidivisional firm in the United States highlight factors critical not only to the United States' capitalist system but also to Japan's. Indeed, large firms played a dominant role in Japan's economic takeoff in the late 1800s. As these companies grew, they were transformed into professionally managed corporations. Managers, operating in a clear hierarchical chain of command, built up huge companies, such as Nihon Denki (NEC), Toshiba, Mitsubishi Electric, Hitachi, Nippon Steel, Matsushita, and Toyota. In Japanese as in U.S. firms, the visible hand of management was critical to controlling the flow of work, from the input of raw materials to the production of finished goods.

scholarly journals Activity of Ceftaroline and Epidemiologic Trends in Staphylococcus aureus Isolates Collected from 43 Medical Centers in the United States in 2009

2011 ◽  
Vol 55 (9) ◽  
pp. 4154-4160 ◽  
Author(s):  
Sandra S. Richter ◽  
Kristopher P. Heilmann ◽  
Cassie L. Dohrn ◽  
Fathollah Riahi ◽  
Andrew J. Costello ◽  
...  
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
The United States ◽  
Surveillance Program ◽  
Content Type ◽  
Type Iv ◽  
Medical Centers ◽  
High Level ◽  
Resistance Rates

ABSTRACTAStaphylococcus aureussurveillance program was initiated in the United States to examine thein vitroactivity of ceftaroline and epidemiologic trends. Susceptibility testing by Clinical and Laboratory Standards Institute broth microdilution was performed on 4,210 clinically significant isolates collected in 2009 from 43 medical centers. All isolates were screened formecAby PCR and evaluated by pulsed-field gel electrophoresis. Methicillin-resistantS. aureus(MRSA) were analyzed for Panton-Valentine leukocidin (PVL) genes and the staphylococcal cassette chromosomemec(SCCmec) type. All isolates had ceftaroline MICs of ≤2 μg/ml with an MIC50of 0.5 and an MIC90of 1 μg/ml. The overall resistance rates, expressed as the percentages of isolates that were intermediate and resistant (or nonsusceptible), were as follows: ceftaroline, 1.0%; clindamycin, 30.2% (17.4% MIC ≥ 4 μg/ml; 12.8% inducible); daptomycin, 0.2%; erythromycin, 65.5%; levofloxacin, 39.9%; linezolid, 0.02%; oxacillin, 53.4%; tetracycline, 4.4%; tigecycline, 0%; trimethoprim-sulfamethoxazole, 1.6%; vancomycin, 0%; and high-level mupirocin, 2.2%. ThemecAPCR was positive for 53.4% of the isolates. The ceftaroline MIC90s were 0.25 μg/ml for methicillin-susceptibleS. aureusand 1 μg/ml for MRSA. Among the 2,247 MRSA isolates, 51% were USA300 (96.9% PVL positive, 99.7% SCCmectype IV) and 17% were USA100 (93.4% SCCmectype II). The resistance rates for the 1,137 USA300 MRSA isolates were as follows: erythromycin, 90.9%; levofloxacin, 49.1%; clindamycin, 7.6% (6.2% MIC ≥ 4 μg/ml; 1.4% inducible); tetracycline, 3.3%; trimethoprim-sulfamethoxazole, 0.8%; high-level mupirocin, 2.7%; daptomycin, 0.4%; and ceftaroline and linezolid, 0%. USA300 is the dominant clone causing MRSA infections in the United States. Ceftaroline demonstrated potentin vitroactivity against recentS. aureusclinical isolates, including MRSA, daptomycin-nonsusceptible, and linezolid-resistant strains.

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