Enzymatic and antifungal susceptibility profiles of Candida glabrata isolates from paediatric patients and their genetic diversity based on microsatellite length polymorphism.

This study aimed to detect different genotypes of Candida glabrata isolates in paediatric patients with and without neutropenia utilizing microsatellite length polymorphism (MLP) and its correlation with drug resistance and enzymatic activity were assessed. Samples from neutropenic and non-neutropenic patients were collected from November 2020 to November 2021. Thirty-six C. glabrata strains were isolated and identified using classical and molecular methods. Then, C. glabrata isolates were genotyped by the MLP technique, and their antifungal susceptibility was performed based on the CLSI M27 guideline. Eighteen different multi-loci genotypes (G1-G18) were detected based on MLP analysis. Analysis of molecular variance revealed high genetic variation within populations (94%) and low genetic differentiation amongst populations (6%). Also, 40% (n = 4) of isolates from neutropenic patients were non-wild-type for posaconazole, and 30% (n = 3) were resistant to caspofungin. Very strong hemolytic and proteinase activity were seen in 97·2 and 86·1% of isolates. Candida glabrata strains from neutropenic patients were genetically divergent from other populations. The minimum spanning tree shows that observed genotypes were mainly related to previously reported genotypes from Iran, Spain, and China.

The patterns of colonization and antifungal susceptibility of Candida, isolated from preterm neonates in Khorramabad, South West of Iran.

OBJECTIVE: Usually, 7-20% of preterm neonates colonized by Candida species present invasive candidiasis. Candida albicans, and several non-albicans species cause invasive infection with C. albicans being the most dominant agent. In the last two decades, infection due to non-albicans have been increased dramatically due to their low sensitivity to antifungal drugs such as fluconazole. The aim of present study was to evaluate Candida colonization pattern and antifungal susceptibility among preterm neonates from Khorramabad, South west of Iran. MATERIALS AND METHODS: Samples were collected from 80 preterm neonates, cultured on CHROMagar Candida and incubated at 37°C. All recovered isolates were primarily screened based on classical methods and identified by PCR-RFLP targeting the ITS-rDNA regions. Antifungal susceptibility testing of all isolates was performed according to the CLSI method against amphotericin B, caspofungin, itraconazole, fluconazole and voriconazole. RESULTS: Totally 23 isolates of Candida species were recovered from 20 patients (female: male, 50:50) including, C. albicans (18), C. parapsilosis (2) and C. glabrata (1). Furthermore, the blood cultures from two patients were yielded C. albicans and C. parapsilosis so that patient with C. albicans died after five days. Generally, in this study, 9 (39.1%) isolates were resistant to amphotericin B including; 7 (30.4%) C. albicans and 2 (8.7%) C. parapsilosis. In addition, 2 (8.7%) and 4 (17.4%) isolates were also resistant to itraconazole and caspofungin, respectively. CONCLUSION: In conclusion, Candida colonization among preterm neonates is still an important issue in hospitals. In addition, in spite of a significant amphotericin B resistant Candida, voriconazole, fluconazole, and itraconazole are valuable antifungals, due to fully sensitivity to Candida.

Study of bacterial flora in children's with hearing aid earmoulds in Ahvaz, Iran.

The aim of this study was to determine the presence and nature of bacterial flora on hearing aids earmoulds in a children's population. The study population consisted of 119 children referred to Imam Ali and Rudaky Schools in Ahvaz, Iran. Three samples were taken from surface of hearing aids earmoulds; canal in hearing aid wearers and ear without hearing aids earmoulds. The samples were cultured directly onto blood agar and MacConkey agar plates. According to preliminary examination, necessary standard biochemical tests were performed on grown bacteria and the organisms were identified as per standard identification criteria. Totally, 66 samples (61.1%) from hearing aids earmoulds and 124 samples (52.1%) from both ear canal without hearing aids earmoulds were culture positive, which 73 (58.9%) and 51 (41.1%) were from right and left ears, respectively. The majority of isolated bacteria from earmoulds were Coagulase-Negative Staphylococci (CNS) 40 (60.6%) and Polybacterial flora 14 (21.2%) and the least isolated bacteria were Pseudomonas aeruginosa and Staphylococcus aureus. In conclusion, although the majority of isolated bacteria were common normal flora of the ear, however a few pathogens were isolated as well. So, it is very important to educate the people with hearing aids earmoulds about proper cleaning and disinfection procedure to prevent any serious ear canal infection.

Phospholipid molecular species distributions of Candida isolates from the UK and Iran.

AIMS: Some species of Candida have been shown to differ with respect to their polar lipid fingerprints when analysed by fast atom bombardment mass spectrometry (FABMS). The aims of this study were to contribute to the existing body of information by (i) examining representatives of species not previously examined and (ii) seeking strains differences associated with country of origin (UK or Iran). METHODS AND RESULTS: FABMS analysis was performed on extracted lipids of 22 strains representing eight species of Candida. The most abundant anion (19 isolates) in spectra was with mass to charge (m/z) 281, corresponding to C18:1 carboxylate. The major phospholipid analogue anions were m/z 515 and 501 (13 strains). These anions were putatively identified as the phosphatidyl molecular species PA(23 : 2) and PA(22 : 2) respectively. Data for strain pairs were compared using the Pearson's coefficient of linear correlation. The values generated were used to cluster strains by nearest-neighbour linkage, using both carboxylate and phospholipid analogue anion data. Isolates of C. parapsilosis were clearly distinct from other isolates. Iranian isolates tended to cluster together when phospholipid anion data were used. However, if carboxylate anion data were used, four Iranian isolates of C. albicans were tightly clustered with three UK isolates, of which two were C. albicans and one was C. dubliniensis. CONCLUSION: It is concluded that both lower, and higher, mass peaks in FABMS spectra can be of potential value in comparing Candida isolates from different countries and from different species. SIGNIFICANCE AND IMPACT OF THE STUDY: When polar lipids of different Candida species are compared, it is important to bear in mind that geographical differences affect results as has been observed with bacteria in similar studies.

Characterization of polar lipids of oral isolates of Candida, Pichia and Saccharomyces by Fast Atom Bombardment Mass Spectrometry (FAB MS).

AIMS: To characterize fatty acid and phospholipid analogue profiles of oral yeasts. METHODS AND RESULTS: Twenty-seven strains of oral yeasts were cultured on SDA and lipids of freeze-dried cells were extracted and analysed by FAB MS. The most abundant carboxylate anion was m/z 281 (C18 : 1). The most intense phospholipid analogue ions were of PE, PG, PA and PI. Pichia etchellsii contained molecular species of PG and PE, whereas Saccharomyces cerevisiae had PA, PG and PE analogues. Mass spectra revealed that S. cerevisiae and Candida glabrata were distinct from one another and from the other species tested. CONCLUSION: Oral yeasts largely differ with respect to their polar lipids. It is concluded that oral yeast species have distinctive fatty acid and phospholipid analogue anion profiles. SIGNIFICANCE AND IMPACT OF THE STUDY: FAB MS provided novel chemotaxonomic information.