title: [Detection of the first QnrS gene positivity in aquatic Aeromonas spp. isolates in Turkey].
abstract: Aeromonas spp. are oxidase positive, gram-negative, facultative anaerobic bacilli that are widely distributed in aquatic environments. A.hydrophila, A.sobria and A.bestiarum may cause severe infections in both human and cold-blooded animals. Environmental persistance of quinolones that are widely used in both human and veterinary medicine plays an important role in the selection of resistant mutants. Plasmid-mediated resistance is one of the main mechanisms involved in quinolone resistance, and qnr, qepA, aac(6')-Ib-cr, oqxAB genes are identified as resistance determinants. Determination of various types of qnr gene in different bacteria mainly in Enterobacteriaceae, suggests that they are widely distributed in nature. Recently, plasmid-mediated quinolone resistance was defined among Aeromonas species isolated from water. The aim of this study was to investigate the presence of qnr genes among aquatic Aeromonas spp. in Turkey. A total of 45 Aeromonas strains isolated from water and fishes collected from three different geographical regions (Aegean, Mediterranean and Blacksea) in Turkey, were included in the study. The isolates were identified at species level by the use of 16S rDNA-RFLP (Restriction fragment length polymorphism) analysis and multiplex polymerase chain reaction (M-PCR). Among the isolates, 20 were identified as A.sobria, 10 as A.hydrophila, nine as A.salmonicida, four as A.bestiarum and two as A.veronii. The plasmid-mediated quinolone resistance determinants, qnrA, qnrB, qnrC and qnrS genes, were investigated by M-PCR, and sequence analysis was performed for nine qnr-positive isolates. According to the sequence analysis of the genes, qnr genes were characterized in six A.sobria, in two A.bestiarum and in one A.hydrophila isolate (9/45; 20%). When the sequence was compared with GenBank database, this gene was found as qnrS2. All qnrS-positive Aeromonas spp. isolates were ciprofloxacin-susceptible, while five of them were resistant to nalidixic acid. This study is the first research about the plasmid-mediated quinolone resistance and the presence of qnrS2 genes among Aeromonas spp. isolated from fishes and water in Turkey. In conclusion, various resistance genes of aquatic bacteria may constitute a potential risk for the transmission of those genes to other bacteria as well as clinical isolates.
authors.forename: Ertan Emek
authors.initials: EE
authors.lastname: Onuk
authors.affiliation: Ankara Occupational Diseases Hospital, Microbiology Laboratory, Ankara, Turkey. yeliztanriverdi@gmail.com.
authors.forename: Yeliz
authors.initials: Y
authors.lastname: Tanrıverdi Çaycı
authors.forename: Ahmet Yılmaz
authors.initials: AY
authors.lastname: Çoban
authors.forename: Alper
authors.initials: A
authors.lastname: Çiftci
authors.forename: Fikri
authors.initials: F
authors.lastname: Balta
authors.forename: Behire Işıl
authors.initials: BI
authors.lastname: Didinen
authors.forename: Gökmen Zafer
authors.initials: GZ
authors.lastname: Pekmezci
authors.forename: Soner
authors.initials: S
authors.lastname: Altun
authors.forename: Mehtap
authors.initials: M
authors.lastname: Söğüt Ünlü
authors.forename: Aydın
authors.initials: A
authors.lastname: Deveci
mesh_terms: D000333:Aeromonas / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D059038:Black Sea; D004275:DNA, Ribosomal / Q000737:chemistry; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D008522:Mediterranean Sea; D060885:Multiplex Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D015363:Quinolones / Q000494:pharmacology*; D011815:R Factors / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014421:Turkey; D014871:Water Microbiology
chemical_list: D004275:DNA, Ribosomal; D015363:Quinolones; D012336:RNA, Ribosomal, 16S