Molecular identification and antifungal susceptibility pattern of Candida species isolated from HIV infected Patients with candisiasis

Abstract

Background and Purpose: Opportunistic fungal infections have been on a growing
trend since the last two decades. Among the opportunistic fungal agents, Candida
species, Cryptococcus neoformans, and Aspergillus fumigatus account for most of the
life-threatening infections in immunocompromised individuals. Regarding this, the
present study aimed to investigate the molecular identification and antifungal
susceptibility pattern of Candida species isolated from HIV-infected patients.
Materials and Methods: This study was conducted on 80 clinical samples collected
from HIV-infected patients with suspected candidiasis referring to Tagore Medical
College and Hospital, Rathinamangalam and Government Hospital of Thoracic
Medicine, in Chennai, India, for 18 months (i.e., May 2016-December 2017). Phenotypic
and molecular identification was accomplished using internal transcribed spacer region 1
(ITS1) and ITS4 primers. The antifungal susceptibility pattern of the isolates against four
antifungal agents was also determined by both disk diffusion and broth dilution methods.
Results: In the present study, the prevalence of candidiasis was obtained as 75% (n=60).
Candida tropicalis was the predominant identified species. All the emerging species
(i.e., Kodamaea ohmeri, Hanseniaspora opuntiae, and C. orthopsilosis) were identified
through molecular identification since the phenotypic identification was inconclusive. In
terms of the susceptibility pattern, 63.3% and 18.3% of the isolates were resistant to
fluconazole and voriconazole, respectively. Candida albicans was also found to be
resistant to amphotericin B.
Conclusion: Molecular assay led to the identification of K. ohmeri, H. opuntiae, and C.
orthopsilosis, which were multidrug-resistant. This study highlighted the need for the
prompt and timely identification of clinical yeast isolates given the emergence of many
rare species and their capability of causing life-threatening infections and outbreaks. In
the laboratories where molecular diagnostic methods are not available, alternative
services of reference laboratories can be utilized as cost-effective measures. With regard
to the growing prevalence of antifungal drug resistance, antifungal susceptibility testing
should be made mandatory for effective patient management.