2025
Okeleye, Oluwabusayo Israel; Majstorovic, Jovana; Sudharaka, Anupa; Triga, Adriana; Mandalakis, Manolis; Katharios, Pantelis; Mladineo, Ivona
Common carp (Cyprinus carpio) blood cells are modulated by a parasitic antimicrobial peptide, A-2S and Edwardsiella spp. strains Journal Article
In: Fish & Shellfish Immunology, vol. 164, pp. 110427, 2025, ISSN: 10504648.
@article{okeleye_common_2025,
title = {Common carp (\textit{Cyprinus carpio}) blood cells are modulated by a parasitic antimicrobial peptide, A-2S and Edwardsiella spp. strains},
author = {Oluwabusayo Israel Okeleye and Jovana Majstorovic and Anupa Sudharaka and Adriana Triga and Manolis Mandalakis and Pantelis Katharios and Ivona Mladineo},
url = {https://linkinghub.elsevier.com/retrieve/pii/S105046482500316X
/wp-content/uploads/2025/06/2025-Busayo-FSI-26.pdf},
doi = {10.1016/j.fsi.2025.110427},
issn = {10504648},
year = {2025},
date = {2025-06-06},
urldate = {2025-06-06},
journal = {Fish & Shellfish Immunology},
volume = {164},
pages = {110427},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Chalmoukis, Charalampos; Droubogiannis, Stavros; Michalopoulou, Vassiliki A; Triga, Adriana; Sarris, Panagiotis F; Katharios, Pantelis
In: Pathogens, vol. 14, no. 3, pp. 247, 2025, ISSN: 2076-0817.
@article{chalmoukis_development_2025,
title = {Development and Characterization of Fluorescent Protein-Tagged Vibrio harveyi Strains as a Versatile Tool for Studying Infection Dynamics and Strain Interactions},
author = {Charalampos Chalmoukis and Stavros Droubogiannis and Vassiliki A Michalopoulou and Adriana Triga and Panagiotis F Sarris and Pantelis Katharios},
url = {https://www.mdpi.com/2076-0817/14/3/247
/wp-content/uploads/2025/03/2025-Chalmoukis-pathogens-13.pdf},
doi = {10.3390/pathogens14030247},
issn = {2076-0817},
year = {2025},
date = {2025-03-18},
urldate = {2025-03-18},
journal = {Pathogens},
volume = {14},
number = {3},
pages = {247},
abstract = {Fluorescent protein-tagged bacterial strains are widely used tools for studying host-pathogen interactions and microbial dynamics. In this study, we developed and characterized Vibrio harveyi strains genetically modified to express green fluorescent protein (GFP) and red fluorescent protein (RFP). These strains were constructed using triparental mating and evaluated for phenotypic, genomic, and virulence attributes. Genomic analyses revealed strain-specific variations, including mutations in key regulatory and metabolic genes, such as luxO and transketolase. While plasmid acquisition imposed metabolic costs, resulting in altered growth and antibiotic sensitivities in certain transconjugants, others demonstrated robust phenotypic stability. Virulence assays using gilthead seabream larvae revealed that most tagged strains retained moderate pathogenicity, with visualization of co-infections highlighting the potential for studying strain-specific interactions. Furthermore, fluorescent microscopy confirmed the successful colonization and localization of tagged bacteria within host tissues. These findings underscore the utility of GFP- and RFP-tagged Vibrio harveyi as versatile tools for infection dynamics, offering a foundation for future research on strain interactions and pathogen-host relationships.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Fluorescent protein-tagged bacterial strains are widely used tools for studying host-pathogen interactions and microbial dynamics. In this study, we developed and characterized Vibrio harveyi strains genetically modified to express green fluorescent protein (GFP) and red fluorescent protein (RFP). These strains were constructed using triparental mating and evaluated for phenotypic, genomic, and virulence attributes. Genomic analyses revealed strain-specific variations, including mutations in key regulatory and metabolic genes, such as luxO and transketolase. While plasmid acquisition imposed metabolic costs, resulting in altered growth and antibiotic sensitivities in certain transconjugants, others demonstrated robust phenotypic stability. Virulence assays using gilthead seabream larvae revealed that most tagged strains retained moderate pathogenicity, with visualization of co-infections highlighting the potential for studying strain-specific interactions. Furthermore, fluorescent microscopy confirmed the successful colonization and localization of tagged bacteria within host tissues. These findings underscore the utility of GFP- and RFP-tagged Vibrio harveyi as versatile tools for infection dynamics, offering a foundation for future research on strain interactions and pathogen-host relationships.
2024
Triga, Adriana; Issa, Zeenat Atinuke; Smyrli, Maria; Fenske, Linda; Katharios, Pantelis
Virulence and pangenome analysis of Vibrio harveyi strains from Greek and Red Sea marine aquaculture Journal Article
In: Aquaculture, vol. 587, pp. 740839, 2024, ISSN: 00448486.
@article{triga_virulence_2024,
title = {Virulence and pangenome analysis of Vibrio harveyi strains from Greek and Red Sea marine aquaculture},
author = {Adriana Triga and Zeenat Atinuke Issa and Maria Smyrli and Linda Fenske and Pantelis Katharios},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2024/04/2024-Triga-AQUA-preprint-22.pdf
https://linkinghub.elsevier.com/retrieve/pii/S0044848624003004},
doi = {10.1016/j.aquaculture.2024.740839},
issn = {00448486},
year = {2024},
date = {2024-04-19},
urldate = {2024-04-19},
journal = {Aquaculture},
volume = {587},
pages = {740839},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2023
Villa, Yanelys Cantillo; Triga, Adriana; Katharios, Pantelis
Polyinfection in Fish Aeromoniasis: A Study of Co-Isolated Aeromonas Species in Aeromonas veronii Outbreaks Journal Article
In: Pathogens, vol. 12, no. 11, pp. 1337, 2023, ISSN: 2076-0817.
@article{cantillo_villa_polyinfection_2023,
title = {Polyinfection in Fish Aeromoniasis: A Study of Co-Isolated Aeromonas Species in Aeromonas veronii Outbreaks},
author = {Yanelys Cantillo Villa and Adriana Triga and Pantelis Katharios},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/11/2023-Cantillo-Villa-pathogens-58.pdf
https://www.mdpi.com/2076-0817/12/11/1337},
doi = {10.3390/pathogens12111337},
issn = {2076-0817},
year = {2023},
date = {2023-11-13},
urldate = {2023-11-14},
journal = {Pathogens},
volume = {12},
number = {11},
pages = {1337},
abstract = {We studied the phenotypic and genomic characteristics related to the virulence and antibiotic resistance of two Aeromonas strains, which were co-isolated before an outbreak of Aeromonas veronii among diseased seabass on Agathonisi Island, Greece, in April 2015. The first strain, AG2.13.2, is a potentially pathogenic mesophilic variant of Aeromonas salmonicida, and the second, AG2.13.5, corresponds to an Aeromonas rivipollensis related to A. rivipollensis KN-Mc-11N1 with an ANI value of 97.32%. AG2.13.2 lacks the type III secretion system just like other mesophilic strains of A. salmonicida. This characteristic has been associated with lower virulence. However, the genome of AG2.13.2 contains other important virulence factors such as type II and type VI secretion systems, and toxins such as rtxA, aerolysin aer/act, and different types of hemolysins. The strain also carries several genes associated with antibiotic resistance such as the tetE efflux pump, and exhibits resistance to tetracycline, ampicillin, and oxolinic acid. In an in vivo challenge test with gilthead seabream larvae, the A. veronii bv sobria strain AG5.28.6 exhibited the highest virulence among all tested strains. Conversely, both A. salmonicida and A. rivipollensis showed minimal virulence when administered alone. Interestingly, when A. veronii bv sobria AG5.28.6 was co-administered with A. rivipollensis, the larvae survival probability increased compared to those exposed to A. veronii bv sobria AG5.28.6 alone. This finding indicates an antagonistic interaction between A. veronii bv sobria AG5.28.6 and A. rivipollensis AG2.13.5. The co-administration of A. veronii bv sobria AG5.28.6 with Aeromonas salmonicida did not yield distinct survival probabilities. Our results validate that the primary pathogen responsible for European seabass aeromoniasis is Aeromonas veronii bv sobria.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We studied the phenotypic and genomic characteristics related to the virulence and antibiotic resistance of two Aeromonas strains, which were co-isolated before an outbreak of Aeromonas veronii among diseased seabass on Agathonisi Island, Greece, in April 2015. The first strain, AG2.13.2, is a potentially pathogenic mesophilic variant of Aeromonas salmonicida, and the second, AG2.13.5, corresponds to an Aeromonas rivipollensis related to A. rivipollensis KN-Mc-11N1 with an ANI value of 97.32%. AG2.13.2 lacks the type III secretion system just like other mesophilic strains of A. salmonicida. This characteristic has been associated with lower virulence. However, the genome of AG2.13.2 contains other important virulence factors such as type II and type VI secretion systems, and toxins such as rtxA, aerolysin aer/act, and different types of hemolysins. The strain also carries several genes associated with antibiotic resistance such as the tetE efflux pump, and exhibits resistance to tetracycline, ampicillin, and oxolinic acid. In an in vivo challenge test with gilthead seabream larvae, the A. veronii bv sobria strain AG5.28.6 exhibited the highest virulence among all tested strains. Conversely, both A. salmonicida and A. rivipollensis showed minimal virulence when administered alone. Interestingly, when A. veronii bv sobria AG5.28.6 was co-administered with A. rivipollensis, the larvae survival probability increased compared to those exposed to A. veronii bv sobria AG5.28.6 alone. This finding indicates an antagonistic interaction between A. veronii bv sobria AG5.28.6 and A. rivipollensis AG2.13.5. The co-administration of A. veronii bv sobria AG5.28.6 with Aeromonas salmonicida did not yield distinct survival probabilities. Our results validate that the primary pathogen responsible for European seabass aeromoniasis is Aeromonas veronii bv sobria.
Triga, Adriana; Smyrli, Maria; Katharios, Pantelis
In: Microorganisms, vol. 11, no. 5, pp. 1197, 2023, ISSN: 2076-2607.
@article{triga_pathogenic_2023,
title = {Pathogenic and Opportunistic Vibrio spp. Associated with Vibriosis Incidences in the Greek Aquaculture: The Role of Vibrio harveyi as the Principal Cause of Vibriosis},
author = {Adriana Triga and Maria Smyrli and Pantelis Katharios},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/05/2023-Triga-microorganisms-19.pdf
https://www.mdpi.com/2076-2607/11/5/1197},
doi = {10.3390/microorganisms11051197},
issn = {2076-2607},
year = {2023},
date = {2023-05-17},
urldate = {2023-05-17},
journal = {Microorganisms},
volume = {11},
number = {5},
pages = {1197},
abstract = {A monitoring program to follow vibriosis incidents in the Greek marine aquaculture was implemented over the past 13 years. 273 isolates, from various cases originating from eight regions and nine hosts, were collected and characterized. The main aquaculture species of the survey were the European seabass (Dicentrarchus labrax) and the gilthead seabream (Sparus aurata). Various species of Vibrionaceae were associated with vibriosis. Vibrio harveyi had the highest prevalence and was isolated throughout the year from all hosts. During the warm months, Vibrio harveyi prevailed with frequent co-isolations of Photobacterium damselae subsp. damselae and Vibrio alginolyticus, while during spring, other Vibrio species were more abundant, such as Vibrio lentus, Vibrio cyclitrophicus, and Vibrio gigantis. Phylogenetic analysis using the mreB gene and the metabolic fingerprint of the isolates showed great variability within the species of the collection. The severity of the disease and the frequency of outbreaks make vibriosis (that is, mainly attributed to V. harveyi) an important concern for the regional aquaculture sector.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A monitoring program to follow vibriosis incidents in the Greek marine aquaculture was implemented over the past 13 years. 273 isolates, from various cases originating from eight regions and nine hosts, were collected and characterized. The main aquaculture species of the survey were the European seabass (Dicentrarchus labrax) and the gilthead seabream (Sparus aurata). Various species of Vibrionaceae were associated with vibriosis. Vibrio harveyi had the highest prevalence and was isolated throughout the year from all hosts. During the warm months, Vibrio harveyi prevailed with frequent co-isolations of Photobacterium damselae subsp. damselae and Vibrio alginolyticus, while during spring, other Vibrio species were more abundant, such as Vibrio lentus, Vibrio cyclitrophicus, and Vibrio gigantis. Phylogenetic analysis using the mreB gene and the metabolic fingerprint of the isolates showed great variability within the species of the collection. The severity of the disease and the frequency of outbreaks make vibriosis (that is, mainly attributed to V. harveyi) an important concern for the regional aquaculture sector.
Tsertou, Maria Ioanna; Triga, Adriana; Droubogiannis, Stavros; Kokkari, Constantina; Anasi, Grammatiki; Katharios, Pantelis
In: Frontiers in Microbiology, vol. 14, pp. 1078669, 2023, ISSN: 1664-302X.
@article{tsertou_isolation_2023,
title = {Isolation and characterization of a novel Tenacibaculum species and a corresponding bacteriophage from a Mediterranean fish hatchery: Description of Tenacibaculum larymnensis sp. nov. and Tenacibaculum phage Larrie},
author = {Maria Ioanna Tsertou and Adriana Triga and Stavros Droubogiannis and Constantina Kokkari and Grammatiki Anasi and Pantelis Katharios},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2023/03/2023-Tsertou-FroMicro-13.pdf
https://www.frontiersin.org/articles/10.3389/fmicb.2023.1078669/full},
doi = {10.3389/fmicb.2023.1078669},
issn = {1664-302X},
year = {2023},
date = {2023-03-07},
urldate = {2023-03-07},
journal = {Frontiers in Microbiology},
volume = {14},
pages = {1078669},
abstract = {Tenacibaculum larymnensis
sp. nov., a novel species of the
Tenacibaculum
genus was isolated from a commercial fish hatchery in Greece. The novel species is phylogenetically close to
T. discolor
and was biochemically and genetically characterized. The genome of
T
.
larymnensis
has 3.66 Mbps length, 31.83% GC content and the genomic analysis demonstrated that it harbors a wide enzymatic repertoire suggestive of increased degrading capacity but also several virulence factors including hemolysins, secretion systems, transporters, siderophores, pili and extracellular proteins. Using the novel strain, a virulent bacteriophage designated as Tenacibaculum phage Larrie was isolated and characterized. Larrie is a novel Siphovirus with relatively large genome, 77.5 kbps with 111 ORFs, a GC content of 33.7% and an exclusively lytic lifestyle. The new phage-host system can serve as an efficient model to study microbial interactions in the aquatic environment which contribute to the nutrient cycling.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tenacibaculum larymnensis
sp. nov., a novel species of the
Tenacibaculum
genus was isolated from a commercial fish hatchery in Greece. The novel species is phylogenetically close to
T. discolor
and was biochemically and genetically characterized. The genome of
T
.
larymnensis
has 3.66 Mbps length, 31.83% GC content and the genomic analysis demonstrated that it harbors a wide enzymatic repertoire suggestive of increased degrading capacity but also several virulence factors including hemolysins, secretion systems, transporters, siderophores, pili and extracellular proteins. Using the novel strain, a virulent bacteriophage designated as Tenacibaculum phage Larrie was isolated and characterized. Larrie is a novel Siphovirus with relatively large genome, 77.5 kbps with 111 ORFs, a GC content of 33.7% and an exclusively lytic lifestyle. The new phage-host system can serve as an efficient model to study microbial interactions in the aquatic environment which contribute to the nutrient cycling.
sp. nov., a novel species of the
Tenacibaculum
genus was isolated from a commercial fish hatchery in Greece. The novel species is phylogenetically close to
T. discolor
and was biochemically and genetically characterized. The genome of
T
.
larymnensis
has 3.66 Mbps length, 31.83% GC content and the genomic analysis demonstrated that it harbors a wide enzymatic repertoire suggestive of increased degrading capacity but also several virulence factors including hemolysins, secretion systems, transporters, siderophores, pili and extracellular proteins. Using the novel strain, a virulent bacteriophage designated as Tenacibaculum phage Larrie was isolated and characterized. Larrie is a novel Siphovirus with relatively large genome, 77.5 kbps with 111 ORFs, a GC content of 33.7% and an exclusively lytic lifestyle. The new phage-host system can serve as an efficient model to study microbial interactions in the aquatic environment which contribute to the nutrient cycling.
2022
Triga, Adriana; Smyrli, Maria; Katharios, Pantelis
Aeromoniasis Book Section
In: Aquaculture Pathophysiology, pp. 317–327, Elsevier, 2022, ISBN: 9780128122112.
@incollection{triga_aeromoniasis_2022,
title = {Aeromoniasis},
author = {Adriana Triga and Maria Smyrli and Pantelis Katharios},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2022/10/2022-Tringa-chapter-25-Aeromonas-preprint-68.pdf
https://linkinghub.elsevier.com/retrieve/pii/B978012812211200024X},
doi = {10.1016/B978-0-12-812211-2.00024-X},
isbn = {9780128122112},
year = {2022},
date = {2022-01-01},
urldate = {2022-10-12},
booktitle = {Aquaculture Pathophysiology},
pages = {317--327},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
}
2021
Kogiannou, Dimitra; Nikoloudaki, Chrysanthi; Katharios, Pantelis; Triga, Adriana; Rigos, George
Evaluation of absorption and depletion of florfenicol in European seabass textitDicentrarchus labrax Journal Article
In: Veterinary Medicine and Science, vol. 7, no. 3, pp. 987–997, 2021, ISSN: 2053-1095, 2053-1095.
@article{kogiannou_evaluation_2021,
title = {Evaluation of absorption and depletion of florfenicol in European seabass textitDicentrarchus labrax},
author = {Dimitra Kogiannou and Chrysanthi Nikoloudaki and Pantelis Katharios and Adriana Triga and George Rigos},
url = {https://imbbc.hcmr.gr/wp-content/uploads/2021/06/2021-Kogiannou-VetMed-Sci-40.pdf
https://onlinelibrary.wiley.com/doi/10.1002/vms3.415},
doi = {10.1002/vms3.415},
issn = {2053-1095, 2053-1095},
year = {2021},
date = {2021-05-01},
urldate = {2021-06-24},
journal = {Veterinary Medicine and Science},
volume = {7},
number = {3},
pages = {987--997},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2019
Smyrli, Maria; Triga, Adriana; Dourala, Nancy; Varvarigos, Panos; Pavlidis, Michael; Quoc, Viet Ha; Katharios, Pantelis
Comparative study on a novel pathogen of european seabass. Diversity of Aeromonas veronii in the aegean sea Journal Article
In: Microorganisms, vol. 7, no. 11, 2019, ISSN: 20762607.
@article{smyrli_comparative_2019,
title = {Comparative study on a novel pathogen of european seabass. Diversity of Aeromonas veronii in the aegean sea},
author = {Maria Smyrli and Adriana Triga and Nancy Dourala and Panos Varvarigos and Michael Pavlidis and Viet Ha Quoc and Pantelis Katharios},
doi = {10.3390/microorganisms7110504},
issn = {20762607},
year = {2019},
date = {2019-01-01},
journal = {Microorganisms},
volume = {7},
number = {11},
abstract = {Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.