scholarly journals Susceptibility testing of non-tuberculous mycobacteria

2004 ◽  
Vol 25 (4) ◽  
pp. 30
Author(s):  
Leo McKnight
Keyword(s):  
Treatment Outcome ◽  
Susceptibility Testing ◽  
Treatment Success ◽  
Clinical Situation ◽  
Response To Treatment ◽  
In Vitro Testing ◽  
Testing Data ◽  
The Common ◽  
Predict Treatment Failure

There is little consensus about treatment for the diseases caused by the common non-tuberculous mycobacteria (NTM). Guidelines are based largely on retrospective, non-controlled studies. Where susceptibility testing data is available, in vitro testing often correlates poorly or not at all with the clinical response to treatment. Performing non validated susceptibility testing is likely to confuse treatment rather than aid it. In the clinical situation, the only valid indication for performance of susceptibility testing is if the test will produce a result that will help predict treatment outcome. A ?susceptible? result should predict treatment success with that drug. Conversely, the detection of resistance in a susceptibility test should predict treatment failure.

scholarly journals Establishment of In Vitro Susceptibility Testing Methodologies and Comparative Activities of Piperacillin in Combination with the Penem β-Lactamase Inhibitor BLI-489

2008 ◽  
Vol 53 (2) ◽  
pp. 370-384 ◽  
Author(s):  
Peter J. Petersen ◽  
C. Hal Jones ◽  
Aranapakam M. Venkatesan ◽  
Tarek S. Mansour ◽  
Steven J. Projan ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
In Vitro Testing ◽  
The Novel ◽  
Inhibitor Concentration ◽  
Constant Concentration ◽  
In Vitro Susceptibility ◽  
Class A ◽  
In Vitro Susceptibility Testing ◽  
Lactamase Inhibitor

ABSTRACT The novel bicyclic penem inhibitor BLI-489 has demonstrated activity as an inhibitor of class A, C, and D β-lactamases. To determine the combination of piperacillin and BLI-489 to be used in susceptibility testing that would most accurately identify susceptible and resistant isolates, a predictor panel of β-lactamase-producing bacteria was utilized to determine the reliability of the combination of piperacillin-BLI-489 at a constant inhibitor concentration of 2 or 4 μg/ml and at ratios of 1:1, 2:1, 4:1, and 8:1. There were a number of strains that would be falsely reported as susceptible or intermediate if tested with the ratios of 1:1 and 2:1, whereas the constant concentration of 2 μg/ml of BLI-489 and the ratio of 8:1 had a tendency to overpredict resistance. Similar MICs were obtained with piperacillin-BLI-489 in a 4:1 ratio and when BLI-489 was held constant at 4 μg/ml. Based on these results, an in vitro testing methodology employing a constant concentration of 4 μg/ml BLI-489 was used to evaluate the combination of piperacillin-BLI-489 against a larger panel of recently identified clinical isolates. Approximately 55% of all of the enteric bacilli tested were nonsusceptible to piperacillin alone (MIC ≥ 32 μg/ml). However, 92% of these piperacillin nonsusceptible strains were inhibited by ≤16 μg/ml piperacillin-BLI-489; in contrast, only 66% were inhibited by ≤16 μg/ml piperacillin-tazobactam. The combination of piperacillin-BLI-489 also demonstrated improved activity compared to that of piperacillin-tazobactam against the problematic extended-spectrum β-lactamase- and AmpC-expressing strains.

scholarly journals Switching from immediate- to sustained-release psychostimulants in routine treatment of children with attention-deficit hyperactivity disorder

2006 ◽  
Vol 30 (7) ◽  
pp. 247-250 ◽  
Author(s):  
Anne E. Thompson ◽  
Saeed A. Nazir ◽  
Mohammed J. Abbas ◽  
Julie Clarke
Keyword(s):  
Attention Deficit Hyperactivity Disorder ◽  
Sustained Release ◽  
Attention Deficit ◽  
Treatment Success ◽  
Real Life ◽  
Immediate Release ◽  
Clinical Situation ◽  
Response To Treatment ◽  
Hyperactivity Disorder ◽  
Significant Difference

Aims and MethodTo investigate the effectiveness of switching children with attention-deficit hyperactivity disorder (ADHD) from immediate- to sustained-release psychostimulants (Concerta XL, a novel methylphenidate hydro-chloride) and to examine factors associated with treatment success or failure. This was a retrospective study of all such children known to four clinicians in Lincolnshire, over a 2-year period. The initial response to treatment and the response to slow-release psychostimulant as judged by the clinicians were recorded. Data were analysed using the Statistical Package for the Social Sciences version 12.ResultsOf the children who were switched (n=97) and on whom clinical judgement was available (n=92), a statistically significant number (32%) responded poorly (P<0.001). In 26 out of the 97 patients, the switching was considered as a treatment failure and they were switched back to the original immediate-release stimulants. There was no significant-difference with possible confounding variables between children who responded well and those who responded poorly after switching to sustained-release drug.Clinical ImplicationsIn a real-life clinical situation there is a significant failure rate when a child with ADHD is switched from an immediate- to sustained-release psychostimulant. Further studies are needed.

scholarly journals Caspofungin Susceptibility Testing of Isolates from Patients with Esophageal Candidiasis or Invasive Candidiasis: Relationship of MIC to Treatment Outcome

2005 ◽  
Vol 49 (9) ◽  
pp. 3616-3623 ◽  
Author(s):  
Nicholas Kartsonis ◽  
John Killar ◽  
Lori Mixson ◽  
Chao-Min Hoe ◽  
Carole Sable ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Treatment Outcome ◽  
Invasive Candidiasis ◽  
Susceptibility Testing ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Central Laboratory ◽  
Esophageal Candidiasis ◽  
Relationship Of

ABSTRACT The caspofungin clinical trial database offers an opportunity to assess susceptibility results for Candida pathogens obtained from patients with candidiasis and allows for correlations between efficacy outcomes and MICs. Candida isolates have been identified from patients enrolled in four studies of esophageal candidiasis and two studies of invasive candidiasis. The MICs of caspofungin for all baseline isolates were measured at a central laboratory using NCCLS criteria (document M-27A); MICs for caspofungin were defined as the lowest concentration inhibiting prominent growth at 24 h. MICs were then compared to clinical and microbiological outcomes across the two diseases. Susceptibility testing for caspofungin was performed on 515 unique baseline isolates of Candida spp. obtained from patients with esophageal candidiasis. MICs for caspofungin ranged from 0.008 to 4 μg/ml; the MIC50 and MIC90 were 0.5 and 1.0 μg/ml, respectively. Susceptibility testing was also performed on 231 unique baseline isolates of Candida spp. from patients with invasive candidiasis. The majority (∼96%) of MICs were between 0.125 and 2 μg/ml, with MIC50 and MIC90 for caspofungin being 0.5 and 2.0 μg/ml, respectively. Overall, caspofungin demonstrated potent in vitro activity against clinical isolates of Candida species. A relationship between MIC for caspofungin and treatment outcome was not seen for patients with either esophageal candidiasis or invasive candidiasis. Patients with isolates for which the MICs were highest (>2 μg/ml) had better outcomes than patients with isolates for which the MICs were lower (<1 μg/ml). Additionally, no correlation between MIC and outcome was identified for specific Candida species.

scholarly journals Effect of In Vitro Testing Parameters on Ceftazidime-Avibactam Minimum Inhibitory Concentrations

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Tiffany R. Keepers ◽  
Marcela Gomez ◽  
Donald Biek ◽  
Ian Critchley ◽  
Kevin M. Krause
Keyword(s):  
Susceptibility Testing ◽  
Ambient Air ◽  
Medium Composition ◽  
In Vitro Testing ◽  
Acidic Ph ◽  
Broth Microdilution ◽  
Mueller Hinton ◽  
Horse Blood ◽  
Mueller Hinton Broth

Effects of varying in vitro susceptibility testing parameters of the broth microdilution assay on ceftazidime-avibactam MICs were determined and compared to meropenem and piperacillin-tazobactam for 9 Enterobacteriaceae and 4 Pseudomonas aeruginosa isolates. The effect of varying incubation conditions (ambient air or 5% CO2), pH of medium, medium composition (cation-adjusted Mueller Hinton Broth with and without laked horse blood and Haemophilus Test Medium), cation content of the medium, and inoculum density were tested. Most variations had no effect on ceftazidime-avibactam MIC values (no more than a 2-fold change). However, acidic pH or high inoculum resulted in 4- to 16-fold changes in MIC, which was similar to those observed for meropenem and piperacillin-tazobactam under these conditions. Overall, this study shows that slight variations in testing parameters during routine MIC testing will likely have no significant effect on ceftazidime-avibactam MIC values.

scholarly journals In Vitro Susceptibility of Isolates of Francisella tularensis Types A and B from North America

2008 ◽  
Vol 52 (6) ◽  
pp. 2276-2278 ◽  
Author(s):  
Sandra K. Urich ◽  
Jeannine M. Petersen
Keyword(s):  
North America ◽  
Francisella Tularensis ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Laboratory Strain ◽  
In Vitro Susceptibility ◽  
Testing Method ◽  
The Common ◽  
Common Laboratory

ABSTRACT Due to concern that Francisella tularensis, the causative agent of tularemia, may be used as a bioterrorist weapon, the Clinical and Laboratory Standards Institute recently provided a susceptibility testing method with breakpoints. Here, 169 isolates (92 type A and 77 type B) from North America were tested against seven antimicrobial agents (streptomycin, gentamicin, tetracycline, doxycycline, ciprofloxacin, levofloxacin, and chloramphenicol) used for the treatment of tularemia. The MICs for all of the isolates fell within the susceptible range. In addition, all isolates had MICs for erythromycin of 0.5 to 4 μg/ml, in contrast to an MIC of >256 μg/ml for the common laboratory strain LVS (live vaccine strain).

scholarly journals In VitroAntibiotic Susceptibility Pattern of Non-diphtheriae CorynebacteriumIsolates in Ontario, Canada, from 2011 to 2016

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Alefiya Neemuchwala ◽  
Deidre Soares ◽  
Vithusha Ravirajan ◽  
Alex Marchand-Austin ◽  
Julianne V. Kus ◽  
...  
Keyword(s):  
Patient Management ◽  
Susceptibility Testing ◽  
Treatment Options ◽  
Treatment Success ◽  
Antibiotic Susceptibility Testing ◽  
Content Type ◽  
Surveillance Studies ◽  
Corynebacterium Striatum ◽  
Testing Data ◽  
Low Levels

ABSTRACTNon-diphtheriae Corynebacterium-associated disease has been increasingly observed and often presents a conundrum to the treating physician. Analysis of antibiotic susceptibility testing data for 1,970 clinicalCorynebacteriumisolates received between 2011 and 2016 revealed that empirical drug treatment options are limited to vancomycin and linezolid.Corynebacterium striatumwas the most frequently observed species during this study period, along withC. amycolatumandC. pseudodiphtheriticum/C. propinquum. Low levels of susceptibility to penicillin (14.5%), erythromycin (15.1%), and clindamycin (8.7%) were observed for non-diphtheriae Corynebacteriumspecies, while 3.0% of isolates were not susceptible to daptomycin. Similarly, 26.9% and 38.1% ofCorynebacteriumisolates were susceptible to ciprofloxacin and trimethoprim-sulfamethoxazole, respectively. Our data show much lower susceptibility to penicillin than previously reported in the literature and an increasing number of isolates resistant to daptomycin, highlighting the need for continued antibiotic surveillance studies for appropriate patient management and treatment success.

scholarly journals In VitroMIC Values of Rifampin and Ethambutol and Treatment Outcome inMycobacterium aviumComplex Lung Disease

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Byoung Soo Kwon ◽  
Mi-Na Kim ◽  
Heungsup Sung ◽  
Younsuck Koh ◽  
Woo-Sung Kim ◽  
...  
Keyword(s):  
Treatment Outcome ◽  
Lung Disease ◽  
Success Rate ◽  
Antimicrobial Agents ◽  
Treatment Success ◽  
Treatment Success Rate ◽  
Standard Regimen ◽  
Content Type ◽  
Broth Microdilution Method

ABSTRACTAlthough it is known that thein vitroMICs of rifampin and ethambutol are poorly correlated with the clinical response inMycobacterium aviumcomplex (MAC) lung disease (MAC-LD), evidence for this is limited. This study investigated the association between treatment outcome and thein vitroMICs of rifampin and ethambutol in patients with MAC-LD. Among patients diagnosed with macrolide-susceptible MAC-LD between January 2008 and December 2013, 274 patients who were treated with a standard regimen for ≥12 months until August 2017 and whosein vitroMIC results were available were enrolled at a tertiary referral center in South Korea. The MICs of antimicrobial agents were determined using the broth microdilution method. The mean age of the included patients was 60.4 years. The overall treatment success rate was 79.6% (218/274 patients) and tended to decrease with increasing MICs of rifampin and ethambutol, particularly at MICs of ≥8 μg/ml. Treatment success rate was significantly different between MAC isolates with MICs of ≥8 μg/ml for rifampin and ethambutol and those with MICs of <8 μg/ml for rifampin and/or ethambutol (64.9% versus 85.3%,P< 0.001). Multivariate analysis showed that an MIC of ≥8 μg/ml for both drugs and initial sputum acid-fast bacillus (AFB) smear positivity were independent risk factors for an unfavorable response (adjusted odds ratio [OR] = 3.154, 95% confidence interval [CI] = 1.641 to 6.063, andP= 0.001 for an MIC of ≥8 μg/ml; adjusted OR = 2.769, 95% CI = 1.420 to 5.399, andP= 0.003 for initial sputum AFB smear positivity). These findings suggest that thein vitroMICs of rifampin and ethambutol may be related to treatment outcome in MAC-LD.

Urokinase Evaluated with the Experimental Radioactive Embolus

1967 ◽  
Vol 17 (03/04) ◽  
pp. 405-411
Author(s):  
M Hume
Keyword(s):  
Animal Experiment ◽  
Blood Clot ◽  
In Vitro Testing ◽  
Effective Agent

SummaryUrokinase and urokinase-activated plasmin have been given to the dog and rabbit. A thrombolytic state has been induced. Purified urokinase has induced lysis of the experimental radioactive blood clot embolus in the circulation. Demonstration of effectiveness in this animal experiment is hampered by inhibition of the agents in the circulation to a degree much greater than was noted in previous experiments with streptokinase. In vitro testing indicates that under proper conditions urokinase will be an effective agent in the treatment of human thromboembolism.

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