Introduction: The aim of the study was to determine microbiota in the cloacal samples of European herring gulls (Larus argentatus) and to compare a variety of genes encoding antimicrobial resistance in cultivable and non-cultivable bacteria. Material and Methods: Cloacal samples from European herring gulls were collected from a Kaunas city dump. Cultivable microbiota were isolated, their microbial susceptibility was tested, and genes encoding antimicrobial resistance were detected. Additionally, a metagenomic study was performed using Next-Generation Sequencing (NGS). Results: In total, 697 different operational taxonomic units at genus level were detected; however, only 63 taxonomic units were detected at the amount of ≥0.1% of the total number of DNA copies. Catellicoccus marimammalium was found to have the highest prevalence. The bacterial amount of other genera was up to 5% with the most highly prevalent being Psychrobacter (4.7%), Helicobacter (4.5%), unclassified Enterococcaceae (3.2%), Pseudomonas (2.9%), and Brachyspira (2.6%). Conclusions: C. marimammalium are predominant microbiota in the cloacal samples of Larus argentatus. This species of gulls is a reservoir of bacteria carrying a wide-spectrum of genes encoding antimicrobial resistance. The same genes were detected in both cultivable microbiota and in the total DNA of the samples.

Introduction: The aim of the study was to determine microbiota in the cloacal samples of European herring gulls (Larus argentatus) and to compare a variety of genes encoding antimicrobial resistance in cultivable and non-cultivable bacteria.

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.

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.