Molecular Identification and Amphotericin B Susceptibility Testing of Clinical Isolates of Aspergillus From 11 Hospitals in Korea.
10.3343/alm.2015.35.6.602
- Author:
Min Seok HEO
1
;
Jong Hee SHIN
;
Min Ji CHOI
;
Yeon Joon PARK
;
Hye Soo LEE
;
Sun Hoe KOO
;
Won Gil LEE
;
Soo Hyun KIM
;
Myung Geun SHIN
;
Soon Pal SUH
;
Dong Wook RYANG
Author Information
1. Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea. shinjh@chonnam.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Aspergillus;
Amphotericin B;
Identification;
Etest;
CLSI
- MeSH:
Amphotericin B/*pharmacology;
Antifungal Agents/*pharmacology;
Aspergillus/*drug effects/isolation & purification;
DNA, Fungal/chemistry/genetics/metabolism;
Hospitals;
Humans;
Microbial Sensitivity Tests;
Mycoses/diagnosis/microbiology;
Republic of Korea;
Sequence Analysis, DNA;
Tubulin/genetics
- From:Annals of Laboratory Medicine
2015;35(6):602-610
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: We investigated the species distribution and amphotericin B (AMB) susceptibility of Korean clinical Aspergillus isolates by using two Etests and the CLSI broth microdilution method. METHODS: A total of 136 Aspergillus isolates obtained from 11 university hospitals were identified by sequencing the internal transcribed spacer (ITS) and beta-tubulin genomic regions. Minimal inhibitory concentrations (MICs) of AMB were determined in Etests using Mueller-Hinton agar (Etest-MH) and RPMI agar (Etest-RPG), and categorical agreement with the CLSI method was assessed by using epidemiological cutoff values. RESULTS: ITS sequencing identified the following six Aspergillus species complexes: Aspergillus fumigatus (42.6% of the isolates), A. niger (23.5%), A. flavus (17.6%), A. terreus (11.0%), A. versicolor (4.4%), and A. ustus (0.7%). Cryptic species identifiable by beta-tubulin sequencing accounted for 25.7% (35/136) of the isolates. Of all 136 isolates, 36 (26.5%) had AMB MICs of > or =2 microg/mL by the CLSI method. The categorical agreement of Etest-RPG with the CLSI method was 98% for the A. fumigatus, A. niger, and A. versicolor complexes, 87% for the A. terreus complex, and 37.5% for the A. flavus complex. That of Etest-MH was < or =75% for the A. niger, A. flavus, A. terreus, and A. versicolor complexes but was higher for the A. fumigatus complex (98.3%). CONCLUSIONS: Aspergillus species other than A. fumigatus constitute about 60% of clinical Aspergillus isolates, and reduced AMB susceptibility is common among clinical isolates of Aspergillus in Korea. Molecular identification and AMB susceptibility testing by Etest-RPG may be useful for characterizing Aspergillus isolates of clinical relevance.
