Typing and Antifungal Susceptibility of Candida Spp. Isolated from Clinical Samples

In our study, we aimed to identify 100 yeast species fungus isolated from clinical samples sent to microbiology laboratory of our hospital and to determine in vitro activity of various antifungals to these species. 55 of the Candidas were isolated from urine, 18 from respiratory tract, 12 from body fluids, 11 from blood, and 4 from other (3 wound 1 vaginal) samples. 46 of them were C. albicans, 19 were C. glabrata, 14 were C. parapsilosis, 11 were C. keyfr, 9 were C. tropicalis, and 1 was C. krusei. C.albicans is still the most commonly isolated type of candida. Amphotericin B remains one of the most effective antifungal agents. There is increased resistance to fluconazole. Increased resistance in all candida species is an important treatment problem, especially in people with low immune resistance. For this reason, identification of species, antifungal testing and antifungal agent should be treated carefully.


Introduction
Candida species are the most common fungal pathogen affecting humans. These organisms have a wide spectrum of disease ranging from noninvasive superficial infections to deep-tissue infections.
The frequency of both out-of-hospital and nosocomial candida infections increases, especially due to broad-spectrum antibiotic use, intravascular devices and the population of immunosuppressive patients [1,2]. In Candida species, blastoconidia, pseudohyphae, chlamydospore and tube jerm formation, ascospore formation are important in the definition of species. Colonies of Candida species form colonies smelling yeast, with a smooth or wrinkled edge, moist, creamy appearance. They reproduce by means of sexual and asexual spores and are classified based on reproductive patterns [3][4][5]. In the ranking of nosocomial fungal infections, urinary tract infections are the first and fungemiler is the second. It is known that urinary catheter application increases the fungus [6]. Diabetes

Materials and Methods
One hundred Candida strains isolated from different clinical samples from SSK Izmir Training Hospital Microbiology Laboratory were included in the study. C. albicans ATCC 90028, C. krusei ATCC 6258, C. parapsilosis ATCC 90018 were used as standard strain.
Agar (SDA) for primary isolation. From the cultures that were understood to be pure, passages were made to the slanted SDA tubes for use in the advanced stage of the identification. Yeasts were added in 0.5 ml human serum to a small portion of the colony to be tested and mixed. It was incubated at 37 °C for 2.5-3 hours. The specimens were examined by microscope at +40 magnification and the flament shaped structures were evaluated as germ tube. The germ-producing yeast strains were defined as C. albicans [10][11][12].

Results
Of the 100 species of yeasts identified from the samples, 55 were isolated from urine, 12 from various body fluids, 18 from respiratory tract, 11 from blood and 4 from other specimens (3 from wound, 1 from vagina). 46 of the yeast species were named C. albicans, 19 were C. glabrata, 14 were C. parapsilosis, 11 were C. keyfr, 9 were C. tropicalis and 1 were C. krusei (Table 1). Germ tube test was found to be positive (100%) in all yeasts that were typed as C.
albicans. In 90 of 100 licensed yeasts, sensitivity tests were tested by E test method. The distribution of abstracted fungi according to predisposing factors; 4% had diabetes + catheters, 6% had fluconazole use, 17% had antibiotic use + had an underlying disease, urinary catheter or any catheter and received immunosuppressive treatment. In urine samples, fluconazole 41%, fluconazole 47%, and voriconazole resistance 75% were found in C. albicans. 34% fluconazole, 47% itraconazole and 6% voriconazole resistance were found in the Candidias detected in urine except C. albicans.
Fluconazole was isolated in 52% of the C. albicans isolated from the urine samples and itraconazole resistance was found in 30% and voriconazole resistance was 73%. In the non-C. albicans yeasts isolated from the urine samples, 22% fluconazole and 33% itraconazole and 5% voriconazole resistance were found. Amphotericin B resistance was not detected in any of the cases ( Table 2).

Conclusion
In our study, the most common type of candida was C. albicans.
In addition, five different species were identified except C. albicans.
This is a sign of infections that may occur with other candida species other than C. albicans, especially C. glabrata in the future.
The determined fluconazole resistance demonstrates the need for more detailed studies to be conducted in clinical-laboratory cooperation in order to be more careful in the use of this agent and to determine the in vivo response.