Comparison of Two Quinupristin-dalfopristin Susceptibility Testing Methods and Two Interpretive Criteria for Bloodstream Isolates from Korean Hospitals.

, particularly in its multidrug-resistant forms, causes invasive nosocomial infections. Given the limited data comparing the effectiveness of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the CLSI clinical breakpoints (CBPs) for quinupristin-dalfopristin (QD) resistance and the need to evaluate their practical application, we retrospectively investigated the susceptibility patterns of 287 bloodstream isolates from Korean hospitals to QD using the updated EUCAST and CLSI CBPs and two antimicrobial susceptibility testing methods: disk diffusion (DD) and Sensititre broth microdilution (Sensititre). QD resistance rates were 5.

Nosocomial transmission of fluconazole-resistant bloodstream isolates revealed by whole-genome sequencing.

Unlabelled: The clonal transmission of fluconazole-resistant isolates within hospitals has seldom been analyzed by whole-genome sequencing (WGS). We performed WGS on 79 . isolates, comprising 31 isolates from three premature infants with persistent bloodstream infection despite antifungal treatment in the same neonatal intensive care unit (NICU) in 2022 and 48 (27 fluconazole-resistant and 21 fluconazole-susceptible dose-dependent) bloodstream isolates from 48 patients in 15 South Korean hospitals from 2010 to 2022.

Virulence Traits and Azole Resistance in Korean Isolates.

We analyzed the virulence traits and azole resistance mechanisms of 104 isolates collected from 13 Korean hospitals from 1996 to 2022. Of these 104 isolates, 96 (5 blood and 91 ear isolates) belonged to clade II, and 8 (6 blood and 2 other isolates) belonged to clade I. Fluconazole resistance (minimum inhibitory concentration ≥32 mg/L) was observed in 68.

Whole-Genome Sequence Analysis of Isolates from a Patient with Persistent Fungemia and Determination of the Molecular Mechanisms of Multidrug Resistance.

Whole-genome sequencing (WGS) was used to determine the molecular mechanisms of multidrug resistance for 10 serial bloodstream isolates obtained from a neutropenic patient during 82 days of amphotericin B (AMB) or echinocandin therapy. For WGS, a library was prepared and sequenced using a Nextera DNA Flex Kit (Illumina) and the MiseqDx (Illumina) instrument. All isolates harbored the same Msh2p substitution, V239L, associated with multilocus sequence type 7 and a Pdr1p substitution, L825P, that caused azole resistance.

Dynamics and Predictors of Mortality Due to Candidemia Caused by Different Species: Comparison of Intensive Care Unit-Associated Candidemia (ICUAC) and Non-ICUAC.

We investigated mortality and predictors of mortality due to intensive care unit-associated candidemia (ICUAC) versus non-ICUAC by species. This study included all candidemia cases in 11 hospitals from 2017 to 2018 in South Korea. The all-cause mortality rates in all 370 patients with ICUAC were approximately twofold higher than those in all 437 patients with non-ICUAC at 7 days (2.

Disk Diffusion Susceptibility Testing for the Rapid Detection of Fluconazole Resistance in Isolates.

Background: Given the increased fluconazole resistance (FR) among isolates, we assessed the suitability of disk diffusion susceptibility testing (DDT) for the early detection of FR using well-characterized isolates.

Methods: In total, 188 isolates, including 66 (seven Erg11 mutants), 69 (33 Pdr1 mutants), 29 (15 Erg11 mutants), and 24 (eight Erg11 mutants) isolates, were tested in this study. FR was assessed using DDT according to the standard CLSI M44-ED3 method, except that two cell suspensions, McFarland 0.

Evaluation of Two Commercial Broth Microdilution Methods Using Different Interpretive Criteria for the Detection of Molecular Mechanisms of Acquired Azole and Echinocandin Resistance in Four Common Species.

The abilities of the new Vitek 2 AST-YS08 (YS08) and Sensititre YeastOne (SYO) systems to detect the resistances of isolates to azoles and echinocandins were evaluated. In total, 292 isolates, including 28 (6 Erg11 and 2 Fks mutants), 57 (26 Erg11 mutants), 24 (10 Erg11 and 1 Fks mutants), and 183 (39 Pdr1 and 13 Fks mutants) isolates, were tested. The categorical agreements (CAs) between the Clinical and Laboratory Standards Institute (CLSI) method and YS08 fluconazole MICs obtained using clinical breakpoints were 92.

Candida auris Clinical Isolates from South Korea: Identification, Antifungal Susceptibility, and Genotyping.

is an emerging worldwide fungal pathogen. Over the past 20 years, 61 patient isolates of (4 blood and 57 ear) have been obtained from 13 hospitals in Korea. Here, we reanalyzed those molecularly identified isolates using two matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) systems, including Biotyper and Vitek MS, followed by antifungal susceptibility testing, sequencing of the gene, and genotyping.

Multilocus Sequence Typing (MLST) Genotypes of Bloodstream Isolates in Korea: Association With Antifungal Resistance, Mutations in Mismatch Repair Gene (Msh2), and Clinical Outcomes.

bloodstream infection (BSI) isolates from a particular geographic area have been reported to comprise a relatively small number of the major sequence types (STs) by multilocus sequence typing (MLST) analysis. Yet little is known about the characteristics of major ST strains of . To address this question in Korea, we investigated antifungal resistance and non-synonymous mutations of the mismatch repair gene ( mutations) in BSI isolates, as well as associated clinical characteristics, and compared the results according to MLST genotype.

Diversity of clinical isolates of Aspergillus terreus in antifungal susceptibilities, genotypes and virulence in Galleria mellonella model: Comparison between respiratory and ear isolates.

We analyzed the antifungal susceptibility profiles, genotypes, and virulence of clinical Aspergillus terreus isolates from six university hospitals in South Korea. Thirty one isolates of A. terreus, comprising 15 respiratory and 16 ear isolates were assessed.

Antifungal susceptibilities to amphotericin B, triazoles and echinocandins of 77 clinical isolates of cryptic Aspergillus species in multicenter surveillance in Korea.

We investigated the in vitro antifungal susceptibilities of cryptic Aspergillus species from nine Korean hospitals. Based on the CLSI epidemiological cutoff values, resistance rates to amphotericin B, itraconazole, voriconazole, posaconazole and caspofungin were as follows: A. awamori (34 isolates; all 0%), A.