Genetic diversity and antimicrobial susceptibility of motile aeromonads isolated from rainbow trout (Oncorhynchus mykiss, Walbaum) farms

Abstract

A total of 22 motile Aeromonas strains were detected in 48 (18.53%) of 259 fish and 6 (10.71%) of 56 water samples obtained from seven commercial rainbow trout (Oncorhynchus mykiss, Walbaum) farms in the province of Mersin, Turkey. These strains were identified by conventional microbiological techniques and by using an ID32GN system. Of these isolates 20 (91.3%) were identified as Aeromonas hydrophila and 2 (8.7%) as Aeromonas sobria. While 8 of the A. hydrophila strains were isolated from water samples, 12 isolates were from fish samples. Whereas A. hydrophila strains were found in all farms, A. sobria was detected in only two farms. Genetic diversity by arbitrarily primed polymerase chain reaction (AP-PCR) and antimicrobial sensitivity tests were carried out on eight A. hydrophila isolates obtained from water samples, and isolates from seven A. hydrophila and one A. sobria from fish samples. The AP-PCR band patterns of motile aeromonads demonstrated weak similarity to the A. hydrophila reference strain ATCC 7966. Five A. hydrophila strains in the water samples displayed genetic similarity, but three others were different. Aeromonas hydrophila isolates from fish samples possessed slight similarities, and A. sobria was genetically distant to all A. hydrophila strains. An antimicrobial sensitivity test of 16 isolates revealed that 100% were sensitive to gentamicin, 87.5% to sulphamethoxazole-trimethoprim, 62.5% to enrofloxacin, 43.8% to oxytetracycline, 37.5% to neomycin, 18.75% to streptomycin and 6.25% to erythromycin. All isolates were resistant to novobiocin.

Development and validation of glycoprotein‐based native‐subunit vaccine for fish against Aeromonas hydrophila

“…Except for A. hydrophila , isolation of other Aeromonas species such as A. caviae , A. sobria , A. schubertii , A. salmonicida / A. bestiarum and A. veroni from waters and fish has also been reported (Özer et al . ; Onuk et al . ).…”

“…There are some reports about isolation of A. hydrophila from cultured fish such as perchs, breams, carps and especially rainbow trouts ( € Ozt€ urk & Altınok 2014). Except for A. hydrophila, isolation of other Aeromonas species such as A. caviae, A. sobria, A. schubertii, A. salmonicida/ A. bestiarum and A. veroni from waters and fish has also been reported ( € Ozer et al 2009;Onuk et al 2013).…”

Yersinia ruckeri and Pseudomonas fluorescens co‐infection in rainbow trout ( Oncorhynchus mykiss Walbaum, 1792)

“…The disease spreads through the body in the circulatory system and causes an inflammatory response in tissues (Kumar et al, 2015; Monte et al, 2016; Tobback et al, 2007). It was first reported from Turkey by Cagirgan and Yurekliturk (1991) in Izmir, and has subsequently been observed in different locations, including Denizli (Timur & Timur, 1991), Marmara region (Karatas & Candan, 1997), Mersin (Özer et al, 2008), Elazığ and Malatya (Şeker et al, 2012). In addition, the pathogen was found in nearby countries such as Bulgaria (Orozova et al, 2015) and Iran (Soltani et al, 1999; Akhlaghi and Sharifi Yazdi, 2008) with the increasing production numbers.…”

Diagnosis of Aeromonas sobria and Saprolegnia sp. co-infection in rainbow trout fry (Oncorhynchus mykiss)

“…In Turkey, A. sobria was first reported in intestinal tracts of healthy Atlantic salmons (Salmo salar) in Black Sea (Karatas, 1996). This pathogen was also detected in rainbow trout (Oncorhynchus mykiss) (Kayis et al, 2009;Ozer et al, 2009;Durmaz and Turk, 2009;Onuk et al, 2017), gold fish (Carassius auratus) (Korun and Toprak, 2007), green terror (Andinoacara rivulatus) (Şahin et al, 2019), gilthead sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) (Avsever et al, 2012) in Turkey. Wahli et al (2005) declared that A. sobria is a causative agent of ulcerative skin diseases in farmed perch (Perca fluviatilis L.) with high mortality in Switzerland.…”