In vitro evaluation of disc diffusion and agar dilution susceptibility testing of Photobacterium damselae ssp. piscicida

2002 ◽  
Vol 25 (4) ◽  
pp. 245-248 ◽  
Author(s):  
A Thyssen ◽  
F Ollevier
Keyword(s):  
Susceptibility Testing ◽  
Disc Diffusion ◽  
In Vitro Evaluation ◽  
Photobacterium Damselae ◽  
Agar Dilution

In vitro sensitivity of Hungarian Actinobaculum suis strains to selected antimicrobials

2003 ◽  
Vol 51 (1) ◽  
pp. 53-59 ◽  
Author(s):  
I. Biksi ◽  
Andrea Major ◽  
L. Fodor ◽  
Keyword(s):  
Type Strain ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Antimicrobial Sensitivity ◽  
Variable Sensitivity ◽  
Agar Dilution ◽  
Almost All

In vitro antimicrobial sensitivity of 12 Hungarian isolates and the type strain ATCC 33144 of Actinobaculum suis to different antimicrobial compounds was determined both by the agar dilution and by the disc diffusion method. By agar dilution, MIC50 values in the range of 0.05-3.125µg/ml were determined for penicillin, ampicillin, ceftiofur, doxycycline, tylosin, pleuromutilins, chloramphenicol, florfenicol, enrofloxacin and lincomycin. The MIC50 value of oxytetracycline and spectinomycin was 6.25 and 12.5µg/ml, respectively. For ofloxacin, flumequine, neomycin, streptomycin, gentamicin, nalidixic acid, nitrofurantoin and sulphamethoxazole + trimethoprim MIC50 values were in the range of 25-100µg/ml. With the disc diffusion method, all strains were sensitive to penicillin, cephalosporins examined, chloramphenicol and florfenicol, tetracyclines examined, pleuromutilins, lincomycin and tylosin. Variable sensitivity was observed for fluoroquinolones (flumequine, enrofloxacin, ofloxacin), most of the strains were susceptible to marbofloxacin. Almost all strains were resistant to aminoglycosides but most of them were sensitive to spectinomycin. A strong correlation was determined for disc diffusion and MIC results (Spearman's rho 0.789, p<0001). MIC values of the type strain and MIC50 values of other tested strains did not differ significantly. Few strains showed a partially distinct resistance pattern for erythromycin, lincomycin and ampicillin in both methods.

Infection of the Subcutis and Skin of Cats with Rapidly Growing Mycobacteria: A Review of Microbiological and Clinical Findings

2000 ◽  
Vol 2 (1) ◽  
pp. 35-48 ◽  
Author(s):  
R Malik ◽  
D I Wigney ◽  
D Dawson ◽  
P Martin ◽  
G B Hunt ◽  
...  
Keyword(s):  
Oral Therapy ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Clinical Findings ◽  
Disc Diffusion ◽  
In Vitro Susceptibility ◽  
In Vitro Susceptibility Testing

Mycobacteria were isolated and characterised from 49 cats with extensive infections of the subcutis and skin. Cats were generally between 3 and 10 years of age, and female cats were markedly over-represented. All isolates were rapid-growers and identified as either Mycobacteria smegmatis (40 strains) or M fortuitum (nine strains). On the basis of Etest for minimum inhibitory concentration and/or disc diffusion susceptibility testing, all strains of M smegmatis were susceptible to trimethoprim while all strains of M fortuitum were resistant. M smegmatis strains were typically susceptible to doxycycline, gentamicin and fluoroquinolones but not clarithromycin. All M fortuitum strains were susceptible to fluoroquinolones, and often also susceptible to gentamicin, doxycycline and clarithromycin. Generally, M smegmatis strains were more susceptible to antimicrobial agents than M fortuitum strains. Treatment of mycobacterial panniculitis involves long courses of antimicrobial agents, typically of 3–6 months, chosen on the basis of in vitro susceptibility testing and often combined with extensive surgical debridement and wound reconstruction. These therapies will result in effective cure of the disease. One or a combination of doxycycline, ciprofloxacin/enrofloxacin or clarithromycin are the drugs of choice for long-term oral therapy.

scholarly journals Comparison of disc diffusion, E-Test and a modified CLSI broth microdilution method for in vitro susceptibility testing of itraconazole, posaconazole and voriconazole against Madurella mycetomatis

2021 ◽  
Author(s):  
Bertrand Nyuykonge ◽  
Lukas van Amelsvoort ◽  
Kimberly Eadie ◽  
Ahmed H. Fahal ◽  
Annelies Verbon ◽  
...  
Keyword(s):  
Low Income ◽  
Susceptibility Testing ◽  
Fungal Infections ◽  
Disc Diffusion ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Bead Beating ◽  
Broth Microdilution Method ◽  
Madurella Mycetomatis

For many fungal infections, in vitro susceptibility testing is used to predict if an isolate is resistant or susceptible to the antifungal agent used to treat the fungal infection. For Madurella mycetomatis , the main causative agent of mycetoma, in vitro susceptibility testing currently is not performed on a routine basis. The current in vitro susceptibility testing method is labor intensive and sonication must be done to generate a hyphal inoculum. For endpoint visualization, expensive viability dyes are needed. Here we investigated if the currently used in vitro susceptibility method could be adapted to make it amendable for use in a routine setting which can be used in low income countries, where mycetoma is endemic. First, we developed a methodology in which hyphal fragments can be generated without the need for sonication, by comparing different bead beating methodologies. Next, in vitro susceptibility was assessed using standard broth microdilution assays as well as disc diffusion, E-testing and VIPcheck™ methodologies. We demonstrate that after a hyphal suspension is generated by glass bead beating, disc diffusion, E-testing and VIPcheck™ can be used to determine susceptibility towards itraconazole, posaconazole and voriconazole of Madurella mycetomatis . The MICs found with the E-test were comparable to those obtained with our modified CLSI-based broth microdilution in vitro susceptibility assay for itraconazole and posaconazole. Furthermore, we found an inverse relationship between the zone of inhibition and MIC obtained with E-test and the modified CLSI broth microdilution technique.

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.

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