Molecular analysis of Aeromonas spp. isolates carrying plasmid-mediated quinolone resistance genes from food fish in Czech Republic

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62157124%3A16270%2F19%3A43878220" target="_blank" >RIV/62157124:16270/19:43878220 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Molecular analysis of Aeromonas spp. isolates carrying plasmid-mediated quinolone resistance genes from food fish in Czech Republic

Original language description

The aim of the study was to isolate and characterize Aeromonas isolates with reduced susceptibility to ciprofloxacin in food fish bred in Czech Republic, and to assess their potential risks as sources of plasmid-mediated quinolone resistance (PMQR). Four hundred Aeromonas isolates were collected from common carp and trout fish and cultivated on blood agar containing ciprofloxacin (0.05 mg/L). Isolates with reduced susceptibility to quinolones were tested for PMQR and virulence genes using polymerase chain reaction (PCR) and sequencing. Only isolates carrying PMQR genes were subjected to further testing. Presumptive isolates were identified to species level using Matrix-Assisted Laser Desorption/Ionization- Time of Flight mass spectrometry in combination with sequencing of rpoB gene. Susceptibility to a set of four antimicrobials and corresponding resistance genes was determined using agar dilution method and PCR, respectively. Clonality of the isolates was analyzed using pulse-field gel electrophoresis and transferability of PMQR genes was tested using conjugation and transformation experiments. Selected isolates were subjected to whole-genome and plasmid sequencing using Illumina platform to analyze their genetic content, similarities within the genomes, and investigate plasmids carrying PMQR gene, respectively. Overall, 257 (64%, n=400) Aeromonas spp. isolates showed reduced susceptibility to fluoroquinolones and PMQR gene qnrS2 was found in 36 (9%) isolates. Eleven (5%) isolates originated from common carps and were identified as Aeromonas veronii while 25 (56%) isolates obtained from trout fish belonged to Aeromonas salmonicida. Most isolates were resistant to oxolinic acid (100%), flumequine (86%) and oxytetracycline (67%) and had at least 2 virulence genes. A. veronii isolates showed lower virulence, had higher diversity of their genetic profiles and belonged to novel sequence types. In A. veronii, resistance to tetracycline was associated with tet(E) gene. Most A. salmonicida isolates belonged to ST2, carried class 1 integron with dfrA14 gene cassette, tet(A) gene for tetracycline resistance and contained 5 virulence genes. The gene qnrS2 was carried by small mobilizable plasmids (4-20 kb in size) or larger IncU plasmids (&gt;30 kb) as a mobile insertion cassette. This study demonstrates high prevalence of qnrS2 gene for fluoroquinolone resistance in aeromonads in Czech fisheries. Common carp and trout fish may represent a potential source of multiresistant bacteria and antibiotic resistant plasmids for aquatic environment and humans.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

10606 - Microbiology

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů