Evaluation of the first Candida auris isolates reported from Türkiye in terms of identification by various methods and susceptibility to antifungal drugs.

PURPOSE: Candida auris is increasingly being isolated from patients all over the world. It has five clades. In this study, it was aimed to compare the results of biochemical tests obtained using different methods and the antifungal susceptibility profiles of C. auris strains isolated from the first seven cases reported in Türkiye, and evaluate whether this information could be useful as preliminary data in determining the clade of strains in centers that lack the opportunity to apply molecular methods. METHODS: Identification test results obtained using API ID 32 C, API 20 C AUX, VITEK-2 YST, and MALDI-TOF MS; colony color and morphology on Chromagar Candida, CHROMagar Candida Plus media, and cornmeal-Tween 80 agar; susceptibility to antifungals were tested and compared. Antifungal susceptibility test was studied using microdilution method according to the recommendations of EUCAST. Additionally, a pilot study was conducted to investigate the value of CHROMagar Candida Plus. RESULTS: All seven strains were identified as Lachancea kluyveri with API ID 32 C, Rhodotorula glutinis; Cryptococcus neoformans with API 20 C AUX, and C. auris with both VITEK-2 YST and MALDI-TOF MS. MIC values for fluconazole were very high (≥64 mg/L) for all seven strains. It was observed that 11 (37.9%) of 29 Candida parapsilosis strains formed colonies with morphology similar to C. auris on CHROMagar Candida Plus medium, leading to false positivity. CONCLUSIONS: Although there have been many isolations of C. auris in our country in recent years, clade distribution of only a small number of strains is known yet. In this study, when the biochemical properties and antifungal susceptibility profiles of the seven strains were evaluated, it was concluded that they exhibited some characteristics compatible with clade I. It was also observed that strains 1 and 2 may belong to a different clade.

Phenotypic Investigation of Virulence Factors, Susceptibility to Ceragenins, and the Impact of Biofilm Formation on Drug Efficacy in Candida auris Isolates from Türkiye.

Candida auris has emerged as a significant fungal threat due to its rapid worldwide spread since its first appearance, along with its potential for antimicrobial resistance and virulence properties. This study was designed to examine virulence characteristics, the efficacy of ceragenins, and biofilm-derived drug resistance in seven C. auris strains isolated from Turkish intensive care patients. It was observed that none of the tested strains exhibited proteinase or hemolysis activity; however, they demonstrated weak phospholipase and esterase activity. In addition, all strains were identified as having moderate to strong biofilm formation characteristics. Upon determining the minimum inhibitory concentrations (MIC) of ceragenins, it was discovered that CSA-138 exhibited the highest effectiveness with a MIC range of 1-0.5 µg/mL, followed by CSA-131 with a MIC of 1 µg/mL. Also, antimicrobial agents destroyed mature biofilms at high concentrations (40-1280 µg/mL). The investigation revealed that the strains isolated from Türkiye displayed weak exoenzyme activities. Notably, the ceragenins exhibited effectiveness against these strains, suggesting their potential as a viable treatment option.

HCV Genotype Distribution of Patients with Chronic Hepatitis C in Istanbul.

OBJECTIVES: Hepatitis C virus (HCV), which has no protective vaccine, is a common cause of chronic hepatitis, which is a severe public health threat. There are differences in nucleotide and amino acid sequences in different regions of the HCV genome. As a result of these differences, HCV has been shown to have at least seven major genotypes and many subtypes. In Turkey, the prevalence of genotype 1 is between 51.7% and 97.1%, the highest rate among all genotypes, while subtype 1b is the genotype with the highest rate. It is important to detect mixed genotype infection reliably as it causes treatment failure. This study aims to reveal the distribution of the HCV genotypes in our hospital in Istanbul over the years and to contribute to the epidemiological data of Turkey. METHODS: For this purpose, 385 patient samples sent to Sisli Hamidiye Etfal Training and Research Hospital, Clinical Microbiology Laboratory for HCV genotype determination between January 2016 and June 2019 were evaluated retrospectively. Anti-HCV was screened by enzyme immunoassay and confirmation was performed by Line immunoassay. HCV genotyping assays targeting highly conserved 5'UTR and most variable region NS5B regions were used. RESULTS: The most common genotype was genotype 1 (81.3%) with 313 cases and subtypes 1a and 1b were detected at the rates of 10.9% and 67.8%, respectively. In addition, genotype 3, 2, 4, 5 were detected at the rates of 8.8%, 3.4%, 2.9%, 0.8%, respectively and mixed genotype was found in 2.9% of cases. Although genotype 5 is seen in South Africa, it is found in the Middle East region, albeit at a low rate. In our study, it was observed that genotype 5 was detected in different years from patients of Syrian origin. CONCLUSION: In this study, genotype 1 was the most common genotype with a rate of 81.3% and subtype 1b was 67.8%, in accordance with the literature. However, genotypes 3, 2, 4 and 5 were also present at low rates. It is important to monitor these rare genotypes since some of them are dominant in surrounding countries. In addition, 2.9% of HCV mixed genotype was detected and this should be considered concerning management of HCV infection.

Comparative evaluation of the Bruker Biotyper and Vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems for non-albicans Candida and uncommon yeast isolates.

INTRODUCTION: Rapid and accurate diagnosis is critically important in invasive and disseminated fungal infections for appropriate antifungal treatment. HYPOTHESIS: MALDI-TOF MS systems are effective for fast and accurate identification of Candida species. AIM: We aimed to compare two MALDI-TOF MS systems for the rapid identification of non-albicans Candida and rare clinical yeast species. METHODOLOGY: This study included 157 isolates representing 23 yeast species. All isolates were identified using Bruker MALDI Biotyper and VITEK MS systems. If both MALDI-TOF MS systems yielded the same results for a certain isolate, the identification is regarded as correct. We performed internal transcribed spacer (ITS) DNA sequencing on five fungal isolates with discordant species names or that were unidentified by the two MALDI-TOF MS systems. RESULTS: The yeast identification sensitivity of MALDI Biotyper was 98.7%, whereas that of VITEK MS was 96.8%. Both MALDI-TOF MS systems correctly identified all strains belonging to four prevalent species, namely, Candida parapsilosis, Candida tropicalis, Candida glabrata, and Candida krusei. For the 19 rare clinical yeast species, identification rates were 96.7% for MALDI Biotyper and 91.7% for VITEK MS. The ITS sequence analysis of five isolates yielded two Meyerozyma caribbica, two Cyberlindnera fabianii, and one Candida dubliniensis. CONCLUSIONS: This study showed the high performance of both MALDI-TOF MS systems, identifying over 90% of yeast isolates in a short time. The disadvantages of these systems are that some species are not present in the databases and it cannot distinguish closely related species. The sensitivity of MALDI-TOF MS systems constantly improves with the expansion of databases in parallel with taxonomic developments for the identification of rare clinical yeast species.

Early Detection and Control of Methicillin resistant Staphylococcus aureus Outbreak in an Intensive Care Unit.

BACKGROUND: Although Methicillin resistant Staphylococcus aureus (MRSA) is one of the major pathogens of healthcare associated infections, we had only sporadic cases in our intensive care unit (ICU) for years. AIMS: To investigate the sudden increase in the number of MRSA cases in ICU. STUDY DESIGN: Descriptive study. METHODS: From the 5th December 2016 to 26th January 2017, we detected 11 new MRSA cases in ICU. Screening of 73 ICU healthcare workers (HCWs) and screening of 13 patients was performed for outbreak investigation. Nine clinical isolates available in stocks and eight screening MRSA isolates were included in molecular studies. PFGE, spa-mecA-mecC-PVL in-house multiplex PCR assay and spa typing, SCCmec typing were performed for all isolates. Sequence type of the representative strain was determined by Multi-Locus Sequence typing (MLST). RESULTS: All strains were mecA positive, PVL negative, and have the same antimicrobial susceptibility pattern except for two strains. All clinical, two patient screening and three nasal isolates of HCWs showed the same pulsotype, named clone A. The spa type of outbreak isolates is t030 and the SCCmec type is SCCmecIII; the MLST type of representative strain is ST239 (PFGE pulsotype A, ST239-SCCmecIII-t030). Unrelated three isolates had PFGE pulsotype B-SCCmecI-t030, PFGE pulsotype C-SCCmecIII-t459, PFGE pulsotype D-SCCmecIII. CONCLUSION: Molecular typing techniques are the cornerstones for the investigation of outbreaks. Infection control measures, such as enhancing cleaning procedures, promoting hand hygiene, should be enforced in the ICU unit. All patients, including those who have already been discharged to other departments, must be put on contact isolation. HCWs carrying the MRSA strains could be offered decolonization.