scholarly journals Antimicrobial susceptibility of Corynebacterium diphtheriae and Corynebacterium ulcerans in Germany 2011–17

2020 ◽  
Vol 75 (10) ◽  
pp. 2885-2893 ◽  
Author(s):  
Durdica V Marosevic ◽  
Anja Berger ◽  
Gunnar Kahlmeter ◽  
Sarah Katharina Payer ◽  
Stefan Hörmansdorfer ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Corynebacterium Diphtheriae ◽  
First Line ◽  
Susceptibility Data ◽  
Corynebacterium Ulcerans ◽  
Corynebacterium Species ◽  
Clinical Breakpoints ◽  
Surrogate Method

Abstract Background Diphtheria is mainly caused by diphtheria-toxin-producing strains of Corynebacterium diphtheriae and Corynebacterium ulcerans. The recommended first-line antibiotic is penicillin or erythromycin, but reliable susceptibility data are scarce. Objectives To define WT MIC distributions of 12 antimicrobial agents and provide data for the determination of tentative epidemiological cut-off values (TECOFFs) for potentially toxigenic corynebacteria and to evaluate the potential usefulness of a gradient test (Etest) for susceptibility testing of penicillin, erythromycin and clindamycin. Methods For the 421 human or veterinary isolates from the period 2011–17, MICs of 12 antimicrobial agents were determined. Etest performance was evaluated for penicillin, erythromycin and clindamycin. Results MIC distributions were characterized and TECOFFs could be set for 11 out of 24 antibiotic/species combinations. The current EUCAST clinical breakpoints, predominantly determined for Corynebacterium species other than C. diphtheriae and C. ulcerans, divide the WT MIC distributions of penicillin and clindamycin, thereby making reproducible susceptibility testing of C. diphtheriae and C. ulcerans difficult. For erythromycin, 4% of C. diphtheriae and 2% of C. ulcerans had MICs higher than those for WT isolates. Phenotypically detectable resistance to other antibiotics was rare. Etest underestimated MICs of penicillin and lower concentrations needed to be included for erythromycin, while for clindamycin the Etest was not a good surrogate method. Conclusions MIC distributions based on reference broth microdilution for potentially toxigenic Corynebacterium spp. were developed. For five and six agents, TECOFFs were suggested for C. diphtheriae and C. ulcerans, respectively, but for Corynebacterium pseudotuberculosis the number of isolates was too low.

scholarly journals Antimicrobial Susceptibility to Azithromycin among Salmonella enterica Isolates from the United States

2011 ◽  
Vol 55 (9) ◽  
pp. 3985-3989 ◽  
Author(s):  
Maria Sjölund-Karlsson ◽  
Kevin Joyce ◽  
Karen Blickenstaff ◽  
Takiyah Ball ◽  
Jovita Haro ◽  
...  
Keyword(s):  
United States ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
The United States ◽  
Outcome Data ◽  
Content Type ◽  
Susceptibility Data ◽  
Retail Meat ◽  
Clinical Breakpoints

ABSTRACTDue to emerging resistance to traditional antimicrobial agents, such as ampicillin, trimethoprim-sulfamethoxazole, and chloramphenicol, azithromycin is increasingly used for the treatment of invasiveSalmonellainfections. In the present study, 696 isolates of non-TyphiSalmonellacollected from humans, food animals, and retail meats in the United States were investigated for antimicrobial susceptibility to azithromycin. Seventy-twoSalmonella entericaserotype Typhi isolates from humans were also tested. For each isolate, MICs of azithromycin and 15 other antimicrobial agents were determined by broth microdilution. Among the non-TyphiSalmonellaisolates, azithromycin MICs among human isolates ranged from 1 to 32 μg/ml, whereas the MICs among the animal and retail meat isolates ranged from 2 to 16 μg/ml and 4 to 16 μg/ml, respectively. AmongSalmonellaserotype Typhi isolates, the azithromycin MICs ranged from 4 to 16 μg/ml. The highest MIC observed in the present study was 32 μg/ml, and it was detected in three human isolates belonging to serotypes Kentucky, Montevideo, and Paratyphi A. Based on our findings, we propose an epidemiological cutoff value (ECOFF) for wild-typeSalmonellaof ≤16 μg/ml of azithromycin. The susceptibility data provided could be used in combination with clinical outcome data to determine tentative clinical breakpoints for azithromycin andSalmonella enterica.

scholarly journals Comparative Analysis of hmuO Function and Expression in Corynebacterium Species

2007 ◽  
Vol 189 (9) ◽  
pp. 3650-3654 ◽  
Author(s):  
Carey A. Kunkle ◽  
Michael P. Schmitt
Keyword(s):  
Comparative Analysis ◽  
Corynebacterium Diphtheriae ◽  
Partial Reduction ◽  
Iron Source ◽  
Corynebacterium Ulcerans ◽  
Corynebacterium Species ◽  
Iron Utilization

ABSTRACT We have constructed defined deletions in the hmuO gene from Corynebacterium diphtheriae and Corynebacterium ulcerans and show that the C. ulcerans hmuO mutation results in a significant reduction in hemoglobin-iron utilization, whereas in C. diphtheriae strains, deletion of hmuO caused no or only partial reduction in the utilization of heme as an iron source. We also show that expression from the C. ulcerans hmuO promoter exhibits minimal regulation by iron and heme whereas transcription from the C. diphtheriae hmuO promoter shows both significant iron repression and heme-dependent activation. These findings indicate that variability in HmuO function and expression exists among Corynebacterium species.

scholarly journals In Vitro Antimicrobial Susceptibility Testing of Helicobacter felis, H. bizzozeronii, and H. salomonis

2005 ◽  
Vol 49 (7) ◽  
pp. 2997-3000 ◽  
Author(s):  
K. Van den Bulck ◽  
A. Decostere ◽  
I. Gruntar ◽  
M. Baele ◽  
B. Krt ◽  
...  
Keyword(s):  
Antimicrobial Agent ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Acquired Resistance ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Helicobacter Felis ◽  
Agar Dilution

ABSTRACT The susceptibilities of Helicobacter felis (15 strains), H. bizzozeronii (7 strains), and H. salomonis (3 strains) to 10 antimicrobial agents were investigated by determination of the MIC using the agar dilution method. No consistent differences were noticed between the different Helicobacter species, which were all highly susceptible to ampicillin, clarithromycin, tetracycline, tylosin, enrofloxacin, gentamicin, and neomycin, as demonstrated by low MICs. Higher MICs were obtained for lincomycin (up to 8 μg/ml) and spectinomycin (up to 4 μg/ml). Two H. felis strains showed a MIC of 16 μg/ml for metronidazole, suggesting acquired resistance to this antimicrobial agent.

scholarly journals Susceptibility of Bifidobacteria of Animal Origin to Selected Antimicrobial Agents

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sigrid Mayrhofer ◽  
Christiane Mair ◽  
Wolfgang Kneifel ◽  
Konrad J. Domig
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Animal Origin ◽  
Regulatory Agencies ◽  
Safety Criterion ◽  
Multimodal Data ◽  
Susceptibility Data ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Micro Organisms

Strains of the genus Bifidobacterium are frequently used as probiotics, for which the absence of acquired antimicrobial resistance has become an important safety criterion. This clarifies the need for antibiotic susceptibility data for bifidobacteria. Based on a recently published standard for antimicrobial susceptibility testing of bifidobacteria with broth microdilution method, the range of susceptibility to selected antibiotics in 117 animal bifidobacterial strains was examined. Narrow unimodal MIC distributions either situated at the low-end (chloramphenicol, linezolid, and quinupristin/dalfopristin) or high-end (kanamycin, neomycin) concentration range could be detected. In contrast, the MIC distribution of trimethoprim was multimodal. Data derived from this study can be used as a basis for reviewing or verifying present microbiological breakpoints suggested by regulatory agencies to assess the safety of these micro-organisms intended for the use in probiotics.

scholarly journals Antimicrobial resistance surveillance of Salmonella isolates from the First People’s Hospital of Yunnan Province, China

2015 ◽  
Vol 9 (04) ◽  
pp. 333-337 ◽  
Author(s):  
Jiang Yaxian ◽  
Zuo Hui ◽  
Niu Hua ◽  
Mao Xiaoqin ◽  
Li Fengliang ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Yunnan Province ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Common Disease ◽  
First Line ◽  
Salmonella Spp ◽  
Resistant Phenotype ◽  
Resistance Rates

Introduction: Typhoid fever is a common disease in Yunnan province; however, the resistant phenotype and epidemic characteristics of Salmonella in this area are still unclear. In this study, a 15-year surveillance of antimicrobial susceptibility of Salmonella is reported. Methodology: From January 1999 to December 2013, Salmonella isolates were recovered from patients in the First People's Hospital of Yunnan Province. Antimicrobial susceptibility was detected and data were analyzed using WHONET5.6. Results: A total of 845 Salmonella isolates were recovered between 1999 and 2013. The most frequently isolated Salmonella serovar was S. Paratyphi A (93%), and 75.1% (635/845) of the isolates were from the young and middle-aged population. The resistance rates of Salmonella spp. to ciprofloxacin, ampicillin, and ceftriaxone increased dramatically during the 15 years. Carbapenems retained the highest and most stable activity against isolates. The resistance rates of all Salmonella isolates to chloramphenicol and sulfamethoxazole were 0.4% (3/845) and 1.8% (15/845), respectively. Conclusions: As Salmonella isolates have been observed to be resistant to first-line antibiotics, antimicrobial agents should be used rationally and prescriptions should be based on case-by-case susceptibility testing.

scholarly journals Role of Antifungal Susceptibility Testing in Non-Aspergillus Invasive Mold Infections

2016 ◽  
Vol 54 (6) ◽  
pp. 1638-1640 ◽  
Author(s):  
Frédéric Lamoth ◽  
Lauro Damonti ◽  
Barbara D. Alexander
Keyword(s):  
Therapeutic Response ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Drug Efficacy ◽  
Antifungal Drug ◽  
First Line ◽  
Content Type ◽  
Clinical Breakpoints ◽  
Invasive Mold Infections

No clinical breakpoints are available to delineate antifungal drug efficacy in non-Aspergillusinvasive mold infections (NAIMIs). In this analysis of 39 NAIMI episodes, the MIC of the first-line antifungal drug was the most important predictor of therapeutic response. For amphotericin B, an MIC of ≤0.5 μg/ml was significantly associated with better 6-week outcomes.

Antimicrobial resistance in swine production

2008 ◽  
Vol 9 (2) ◽  
pp. 135-148 ◽  
Author(s):  
Frank M. Aarestrup ◽  
C. Oliver Duran ◽  
David G. S. Burch
Keyword(s):  
Antimicrobial Resistance ◽  
Human Health ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Acquired Resistance ◽  
Swine Production ◽  
Susceptibility Data ◽  
Development Of Resistance ◽  
The World ◽  
Different Parts

AbstractLarge amounts of antimicrobial agents are still being used in modern swine production in many countries around the world. This facilitates the emergence and development of antimicrobial resistance. Bacteria causing infections in swine have in several cases acquired resistance to a number of the agents most commonly used for treatment, making it difficult to predict the efficacy of different antimicrobial agents without prior susceptibility testing. This review gives an overview of recent susceptibility data from different parts of the world and discusses the importance of the development of resistance not only in the treatment of infections in swine but also taking into account the human health implications of antimicrobial resistance.

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