An Outbreak of tet(X6)-Carrying Tigecycline-Resistant Acinetobacter baumannii Isolates with a New Capsular Type at a Hospital in Taiwan

Yu-Chia Hsieh; Jia-Wen Wu; Yi-Yin Chen; Tran Lam Tu Quyen; Wei-Chao Liao; Shiao-Wen Li; Yin-Cheng Chen; Yi-Jiun Pan

doi:10.3390/antibiotics10101239

Antibiotics (Oct 2021)

An Outbreak of tet(X6)-Carrying Tigecycline-Resistant Acinetobacter baumannii Isolates with a New Capsular Type at a Hospital in Taiwan

Yu-Chia Hsieh,
Jia-Wen Wu,
Yi-Yin Chen,
Tran Lam Tu Quyen,
Wei-Chao Liao,
Shiao-Wen Li,
Yin-Cheng Chen,
Yi-Jiun Pan

Affiliations

Yu-Chia Hsieh: Department of Pediatrics, Chang Gung Children’s Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan 333, Taiwan
Jia-Wen Wu: Department of Microbiology and Immunology, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan
Yi-Yin Chen: Department of Pediatrics, Chang Gung Children’s Hospital, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan 333, Taiwan
Tran Lam Tu Quyen: Department of Microbiology and Immunology, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan
Wei-Chao Liao: Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan
Shiao-Wen Li: Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan
Yin-Cheng Chen: Molecular Medicine Research Center, Chang Gung University, Taoyuan 333, Taiwan
Yi-Jiun Pan: Department of Microbiology and Immunology, School of Medicine, College of Medicine, China Medical University, Taichung 404, Taiwan

DOI: https://doi.org/10.3390/antibiotics10101239
Journal volume & issue: Vol. 10, no. 10
p. 1239

Abstract

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Dissemination of multidrug-resistant, particularly tigecycline-resistant, Acinetobacter baumannii is of critical importance, as tigecycline is considered a last-line antibiotic. Acquisition of tet(X), a tigecycline-inactivating enzyme mostly found in strains of animal origin, imparts tigecycline resistance to A. baumannii. Herein, we investigated the presence of tet(X) variants among 228 tigecycline-non-susceptible A. baumannii isolates from patients at a Taiwanese hospital via polymerase chain reaction using a newly designed universal primer pair. Seven strains (3%) carrying tet(X)-like genes were subjected to whole genome sequencing, revealing high DNA identity. Phylogenetic analysis based on the PFGE profile clustered the seven strains in a clade, which were thus considered outbreak strains. These strains, which were found to co-harbor the chromosome-encoded tet(X6) and the plasmid-encoded blaOXA-72 genes, showed a distinct genotype with an uncommon sequence type (Oxford ST793/Pasteur ST723) and a new capsular type (KL129). In conclusion, we identified an outbreak clone co-carrying tet(X6) and blaOXA-72 among a group of clinical A. baumannii isolates in Taiwan. To the best of our knowledge, this is the first description of tet(X6) in humans and the first report of a tet(X)-like gene in Taiwan. These findings identify the risk for the spread of tet(X6)-carrying tigecycline- and carbapenem-resistant A. baumannii in human healthcare settings.

Published in Antibiotics

ISSN: 2079-6382 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Medicine: Therapeutics. Pharmacology
Website: http://www.mdpi.com/journal/antibiotics

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