Aeromonas hydrophila and Campylobacter jejuni are bacteria of emerging importance in public health. However, little has been published about fish contaminated by these pathogens. The present study aimed to verify the presence of Aeromonas hydrophila and Campylobacter jejuni in fresh tuna samples (Thunnus spp.) caught off the coast of Santa Catarina State and distributed in the wholesale market of São Paulo/SP. A total of 85 tuna fillet samples were collected and examined by PCR and bacteriological analyses. Aeromonas spp. was detected in 11/85 (13%) samples, with 10/11 (90.9 %) being confirmed as Aeromonas hydrophila by PCR. Campylobacter spp. was found in 10/85 (11.7%) samples, 10/10 (100%) identified as Campylobacter jejuni by PCR and conventional biochemical analyses. Both pathogens were found in 2/85 (2.3%) samples. This is the first report on the contamination of fresh tuna by Campylobacter jejuni and Aeromonas hydrophila in Brazil. In addition to show that tuna can be a vehicle for transmission of pathogens when consumed raw, it emphasizes the importance of further studies to support the control these pathogens in fish.

Introduction: In the present study, some of the commercial fish farms located in the Black Sea region of Turkey, were screened for bacteria between 2012 and 2014.Material and Methods: The bacterial agents isolated from fish were identified by classical biochemical tests and the rapid diagnostic tests (API 20 E and API 20 Strep). All strains were further identified by sequencing of the 16S rRNA genes. The strains were also investigated for resistance to different antimicrobials by the disc diffusion method. Antibiotic resistance genes, including tetracycline (B), β-lactam (ampC, blaTEM, blaPSE), florfenicol (floR), erythromycine (ereA, ereB), sulphonamide (sulI, sulII), and trimethoprim (dhfr1) genes, were determined by the PCR method.Results:Vibrio anguillarum, Vibrio fluvialis, Photobacterium damselae subsp. piscicida, Pseudomonas luteola, Lactococcus garvieae, Streptococcus iniae, Aeromonas hydrophila, and Yersinia ruckeri were isolated from marine and freshwater cultured fish. According to the results of disc diffusion, all isolates were sensitive to florfenicol, trimethoprim+sulfamethoxazole, oxitetracycline, and enrofloxacin, and resistant to lincomycin, penicillin G, and amoxicillin. Also, sulI, sulII, and floR resistance genes were detected in the bacteria.Conclusion: The results of the study open up the opportunity to perform further investigations which could determine the possible role of ARGs in fish pathogens.