Genomic characterisation and epidemiology of nosocomial Serratia marcescens isolates resistant to ceftazidime and their plasmids mediating rare bla TEM-61
Autor: | Noriyuki Nagano, Eiji Soga, Satoshi Yoshida, Katsutoshi Izumi, Shota Koide, Wataru Hayashi, Yukiko Nagano, Shino Takizawa, Yoshichika Arakawa |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
0301 basic medicine
Microbiology (medical) Ceftazidime resistance 030106 microbiology Immunology Ceftazidime Single-nucleotide polymorphism Tn1 Biology Microbiology DNA sequencing 03 medical and health sciences 0302 clinical medicine Plasmid Nosocomial spread Genotype medicine Immunology and Allergy 030212 general & internal medicine Gene Serratia marcescens Genetics Phylogenetic tree biology.organism_classification QR1-502 blaTEM-61 bla(TEM-61) medicine.drug |
Zdroj: | Journal of Global Antimicrobial Resistance, Vol 25, Iss, Pp 124-131 (2021) |
ISSN: | 2213-7173 |
Popis: | Objectives: We determined the whole DNA sequences of plasmids carrying a rare extended-spectrum beta-lactamase gene (bla(TEM-61)) to precisely understand the spread of resistance among nosocomial Serratia marcescens populations. Methods: Twenty non-duplicate ceftazidime-resistant S. marcescens nosocomial isolates (ceftazidime MICs, 32 to >128 mg/L) collected over 1 year were pulsotyped and nucleotide sequences of the bla(TEM-61) gene and its promoter region were determined. Twelve representative isolates were analysed by whole-genome sequencing. Results: The 20 isolates comprised two distinct pulsotypes: I (14 isolates) and II (6 isolates). They all contained the bla(TEM-61) gene. A polymorphism in the repeat number of a 15-nucleotide sequence (5'-ATGTCATGATAATAA-3') was found in the promoter region of bla(TEM-61); two, three and four repeat units were found in 6,12 and 2 isolates, respectively. Single nucleotide polymorphism (SNP)-based phylogenetic analysis of 12 isolates revealed that 7 isolates of pulsotype I (12-44 SNP differences) and 5 isolates of pulsotype II (15-55 SNP differences) formed two distinct clusters of genotypes 1 and 2, respectively. All 12 isolates harboured a plasmid carrying the Tn1-bla(TEM-61) element, although they were slightly different in size (78 883 bp, 78 898 bp and 78 913 bp) owing to differences in the number of 15-bp repetitive sequences. A 42 542-bp broad-host-range plasmid carrying the Tn1-bla(TEM-61) element was also found in one of the isolates. Conclusions: We characterised a plasmid-encoded novel Tn1-bla(TEM-61) element and transposon-dependent mechanisms underlying the propagation of antibiotic resistance, together with repeated new polymorphic 15-bp units in the promoter of bla(TEM-61). (C) 2021 The Author(s). Published by Elsevier Ltd on behalf of International Society for Antimicrobial Chemotherapy. Article Journal of Global Antimicrobial Resistance 25 : 124-131(2021) |
Databáze: | OpenAIRE |
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