Affiliation:
1. Faculty of Pharmacy, University of Science & Technology , Omdurman , Sudan
2. Department of Medical Microbiology and Infectious Diseases, Erasmus MC, University Medical Center Rotterdam , Rotterdam , the Netherlands
Abstract
Abstract
Objectives
Actinomycetoma is a chronic granulomatous disease affecting skin, subcutaneous tissue, fascia, muscle and bones. With increasing resistance against commonly used treatment regimens, susceptibility testing is urgently needed.
Methods
We developed an in vitro susceptibility assay for Actinomadura madurae, one of the common causative agents of actinomycetoma, employing resazurin for endpoint reading. Using this assay, reproducible MICs were determined for the most commonly used antibacterial agents for actinomycetoma treatment. The tested antibacterial agents included trimethoprim/sulfamethoxazole, amikacin, streptomycin, amoxicillin, ceftriaxone, gentamicin, ciprofloxacin, doxycycline, imipenem, linezolid, penicillin G and rifampicin.
Results
Following the clinical breakpoints as stated by CLSI, 100% of the tested strains were susceptible to trimethoprim/sulfamethoxazole (MIC 0.03/0.59–1/19 mg/L), amikacin (MIC 0.0078–0.25 mg/L), doxycycline (MIC <0.25–1 mg/L) and linezolid (MIC <0.25–2 mg/L), 90% to ciprofloxacin (MIC <0.25–2 mg/L), 80% to ceftriaxone (MIC <0.5 to >64 mg/L) and imipenem (MIC <0.25–32 mg/L) and only 20% to amoxicillin (MIC <0.5 to >64 mg/L) and rifampicin (MIC 0.5 to >32 mg/L).
Conclusions
Determinations of MICs by visual readings of colour changes versus spectrophotometric readings were comparable. This convenient visual reading has the advantage of feasible implementation in endemic settings.
Publisher
Oxford University Press (OUP)
Subject
Infectious Diseases,Pharmacology (medical),Pharmacology,Microbiology (medical)