THE PRESENCE OF PUTATIVE VIRULENCE DETERMINANTS, TETRACYCLINE AND β-LACTAMS RESISTANCE GENES OF Aeromonas SPECIES ISOLATED FROM PET TURTLES AND THEIR ENVIRONMENT

Abstract

This study aimed to characterize Aeromonas spp. isolated from ten popular species of pet turtles and their environment to evaluate the potential risk of pet turtles as a source of virulence-associated genes, and tetracycline and β-lactams resistance determinants. Presence of eight virulence genes (ser, aer, exu, lip, fla, ascV, ahyB and gcat), and tetracycline (tetA, tetB and tetE) and β-lactams (blaTEM, blaSHV, blaOXA and blaCTX-M) resistance genes were evaluated by conventional PCR assays. The aerA gene showed the highest frequency of occurrence (92%), followed by fla (75%), gcaT (68%), ahyB (59%), ser (39%), lip (37%) and ascV (25%) genes. None of the isolates carried amplicon of DNase-associated exu gene. A. hydrophila, A. dharkensis, A. veronii and A. caviae were carried seven tested virulence genes except for exu while only four virulence genes were detected in A. enteropelogenes. Among the 75 tetracycline-resistant isolates, tetA, tetE and tetB genes were detected in 38, 26 and 6 isolates, respectively. Among the tested β-lactam resistance genes, blaOXA and blaTEM genes were detected in 54% and 36% of β-lactam resistant isolates, respectively. No blaCTX-M and blaSHV genes were detected. Our results indicate that pet turtle-associated aeromonads, exhibiting potential virulence and antimicrobial (tetracycline and β-lactams) resistance genes, may pose a serious health risk to pet turtle owners, particularly to immunocompromised individuals. Key words: Aeromonas spp.; virulence-associated genes; tetracycline resistance; β-lactams resistance; pet turtle PRISOTNOST DETERMINANT ZA DOLOČITEV DOMNEVNE VIRULENCE TER GENOV ZA ODPORNOST NA TETRACIKLIN IN β-LAKTAM VRST Aeromonas IZOLIRANIH IZ LJUBITELJSKIH VRST ŽELV IN IZ NJIHOVEGA OKOLJA Izvleček: Namen študije je bil določiti bakterije Aeromonas spp., izolirane iz desetih priljubljenih vrst hišnih želv in njihovega okolja, z namenom ocenjevanja potencialnega tveganje hišnih želv kot vira genov, povezanih z virulenco, ter determinante odpornosti proti tetraciklinom in β-laktamom. Prisotnost osmih virulentnih genov (ser, aer, exu, lip, fla, ascV, ahyB in gcat) ter genov za odpornost na tetracikline (tetA, tetB in tetE) in β-laktame (blaTEM, blaSHV, blaOXA in blaCTX-M) je bila ocenjena s konvencionalnimi testi PCR. Najbolj pogost je bil Gen aerA (92 %), sledili so geni fla (75 %), gcaT (68 %), ahyB (59 %), ser (39 %), lip (37 %) in ascV (25 %). Nobeden od izolatov ni imel pomnoženega gena exu, povezanega z DNAzo. A. hydrophila, A. dharkensis, A. veronii in A. caviae so vsebovali sedem testiranih genov virulence, razen exu, medtem ko so bili v A. enteropelogenih odkriti le štirje virulenčni geni. Med 75 izolati, odpornimi na tetracikline, so bili geni tetA, tetE in tetB odkriti v 38, 26 oziroma 6 izolatih. Med preizkušenimi geni za odpornost proti β-laktamu so bili geni blaOXAin blaTEM odkriti pri 54 % oziroma 36 % izolatov, odpornih proti β-laktamu. V nobenem vzorcu nista bila zaznana gena blaCTX-M in blaSHV. Rezultati študije kažejo, da bakterije Aeromonas spp. iz hišnih želv lahko imajo potencialne virulenčne gene in gene za odpornost proti tetraciklinu in β-laktamom, in lahko potencialno ogrožajo zdravje lastnikov hišnih želv, zlasti imunsko oslabljenih posameznikov. Ključne besede: Aeromonas spp.; geni povezani z virulenco; odpornost na tetracikline; rezistenca na β-laktami; ljubiteljske vrste želv