Antifungal Susceptibility of Oral Candida Species Isolated from Patients with Thalassemia Major

Abstract

Background: Invasive fungal infections are the primary cause of morbidity and mortality in patients with thalassemias. This high mortality rate stems, in part, from the prevalence of resistance to antifungal agents. Candida species remain the most common cause of invasive fungal infection in patients with thalassemia. Nevertheless, other Candida species become increasingly spreading and need to be identified to a species level.Objectives: The objectives of the study were to estimate the prevalence of Candida infection among Thalassemia major patients compared to healthy controls and to identify the resistance patterns among the recovered species.Methods: A total of 60 oral samples were collected from two groups: Group I: 40 oral swabs were collected from patients clinically diagnosed with thalassemia major from the out-patient clinics of Pediatric department in Ain Shams University Hospital. Group II: 20 oral swabs were collected from healthy subjects matched in age and sex with the patients' group. The swabs were cultured onto both CHROM and Sabaroud's agar media. The recovered colonies on Sabaroud's agar were identified using Gram stain and Germ tube test while the colonies on CHROM agar were self-identified through color produced according to manufacturer instructions. For all identified colonies API 20 C AUX was used as a confirmatory test. Antifungal Susceptibility testing using Fluconazole (25μg).Voriconazole (1μg).Nystatin (100 units) was used to identify the resistance strains.Results: C. albicans, were isolated from 69.2% of cases while 30.8% were non C. albicans. (23% C. tropicalis and 7.8% C. krusei). Susceptibility testing for all identified colonies revealed that (13.8%) of all isolates were resistant to fluoconazole, (17.3%) to voriconazole and (89.7%) to nystatin. Conclusion:The use of CHROM agar media offers multiple advantages without increasing costs in comparison to other procedures. CHROM agar media have equal or greater sensitivity of detection, superior detection of mixed cultures as a result of better visualization of different species, and enable shorter times to report results. Antifungal susceptibility tests are now required to optimize antifungal treatment to avoid emergence of new resistant strains.