Clinical, microbiological and molecular studies of invasive pulmonary aspergillosis caused by Aspergillus lentulus in China

Shu-Ying Yu, Menglan Zhou, Yingchun Xu

Author address: 

Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China

Abstract: 

Background: Here is the first study aimed at clinical, microbiological and molecular characteristics of Aspergillus lentulus from invasive aspergillosis (IA) patients in China.

Materials/methods: A panel of six non-duplicate A. lentulus isolates recovered from respiratory tract of patients with proven or probable IA under the China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program during August 2016 to July 2017. Accurate identification and phylogenetic analysis of all the isolates were based on multi-locus sequence typing (MLST) of five genes. Seven microsatellite markers employed for A. lentulus genotyping .The identification of all the isolates were further explored using two MALDI-TOF MS systems. The in vitro susceptibility to nine antifungal drugs was determined by CLSI M27-A3 broth microdilution methodology.

Results: A total of six patients in our study were diagnosed as proven or probable IA caused by A. lentulus, associated with fatal outcome. Immunocompromised state, prior antifungal therapy and ICU hospitalization were obvious risk factors for invasive A. lentulus infection. Minor phenotypic characteristics were observed in A. lentulus isolates including slowly growth, reduced sporulation and inability of growth at 48°C, compared with A. fumigatus. ITS sequences were incompetent for distinguishing A. lentulus and A. fumigatus, while benA, CaM and rod A sequences were reliable for distinction to the species level. Phylogenetic analysis further confirmed that ITS region had little variation of Aspergillus section Fumigati while benA gene had highest intraspecific discrimination among the four gene. Microsatellite typing results showed that chromosome1, 3, 5 and 6b were available for A. lentulus. All the A. lentulus isolates in our study were showed in vitro resistance to multiple drugs including amphotericin B (MIC range 4 to 8 μg/ml), itraconazole (MIC 2 μg/ml), voriconazole (MIC range 8 to 16 μg/ml) and posaconazole (MIC range 0.5 to 1 μg/ml). While the MEC range for caspofungin, micafungin and anidulafungin were 0.03 to 0.25, ≤0.08 to 0.15 and ≤0.08 μg/ml, which were classified as wild type against echinocandins.

Conclusions:This study points that A. lentulus as an emerging fatal causative agent worldwide should be concerned by clinicians and laboratories in the future.

Presenter email address: [email protected]

2020

abstract No: 

4939

Full conference title: 

European Congress of Clinical Microbiology and Infectious Diseases 2020
    • ECCMID 30th (2020)