Rapid flow cytometric susceptibility testing of candida species

The present study was performed to establish a standardized rapid antifungal susceptibility method using flow cytometry [FCM]. Also, to detect the antifungal susceptibility pattern of Candida species isolated in Ain Shams University Hospitals. For this purpose, 50 Candida isolates from different patients' specimens [urine, sputum, pus, blood and ascitic fluid] were identified to the species level using Microscan Walkaway 40. Their in vitro susceptibility to amphotericin B [AMB], fluconazole and ketoconazole was performed using 2 reference broth microdilution NCCLS M27-A and FCM. Membrane permeability changes of Candida caused by antifungal agents were measured by FCM using propidium iodide. The most common isolates were C. albicans [48%], C. Tropicalis [40%], and others: C. parapsilosis, C. Lusitaniae, C. glabarata and C. Krusei [12%]. By both methods [M27-A and FCM], Candida species were 90% and 92% susceptible to AMB respectively; 80% and 4% susceptible to ketoconazole respectively and 84% and 88% susceptible to fluconazole respectively. On comparing results of both methods for antifungal susceptibility testing, it was found that by FCM, a 4 hrs incubation for azoles and 2 hrs incubation for AMB were aufficient to provide MICs comparable to the reference M27-A broth microdilution method developed by NCCLS. Subcommittee on antifungal susceptibility tests [correlation significance < 0.001]. Such work showed that FCM provides rapid and sensitive method for antifungal susceptibility of candida

Bacterial multiresistance in clinical practice

Over a period of one year, 202 isolates with antibiotic multiresistant pattern [> 5 antibiotics] were selected from different samples received at Ain Shams University Hospitals laboratories. Pure cultures of isolates were identified by cultural characters and biochemical reactions using conventional methods, modified micro well plates and the new technique of agar plates incorportated with chemical substrate. Susceptibility tests were performed by disk diffusion method and by minimum inhibitory concentration using microdilution broth technique. Multiresistant strains were isolated mainly from wound specimens [46.5%] and urine [45.5%]. They were mostly Ps. pyocyaneus [36.6%] followed by Klebsiella [22.7%] and Staph. aureus [17.8%]. Gram negative organisms showed high resistance [> 90%] towards ampicillin / sulbactam [unasyn], cephalexin and nalidixic acid. Also they shared Staph. aureus in their resistance [> 90%] towards amoxycillin and ampicillin. Such results indicate that an alarming increase in antibiotic resistance has taken place among both gr -ve and gr +ve isolates