Orientador: Elisabeth Criscuolo Urbinati / Banca: Sérgio Fonseca Zaiden / Banca: Marco Antonio de Andrade Belo / Banca: João Batista Kochenborger Fernandes / Banca: Maria José Tavares Ranzani de Paiva / Resumo: Este trabalho avaliou o efeito da administração oral de β-glucano no crescimento, no aproveitamento do alimento, na dinâmica metabólica e nas respostas imunes inatas de juvenis de pacu (Piaractus mesopotamicus) submetidos a ciclos curtos de restrição alimentar e realimentação, e a ação imunoestimulante de β-glucano oferecido por 15 dias na fase final dos ciclos. Um total de 210 peixes foi distribuído em 21 tanques e submetido a diferentes estratégias de alimentação durante sete semanas: GC - Alimentação todo dia com ração comercial (RC); G 6/1- Alimentação com RC por 6 dias e jejum por 1 dia (6/1); G 2/1 - Alimentação com RC por 2 dias e jejum por 1 dia (2/1); GCS - Alimentação todo dia com RC, e com suplementação de 0,5% de β-glucano (RCS), nos últimos 15 dias; GS 6/1 - Alimentação com RC por 6 dias e 1 dia de jejum, e RCS nos últimos 15 dias; GS 2/1 - Alimentação com RC, por 2 dias de alimentação e 1 dia de jejum, e RCS nos últimos 15 dias. Um sétimo grupo (GC-PBS) foi alimentado todos os dias para controle do efeito da manipulação e do veículo da inoculação bacteriana. No dia 50, nove peixes de cada tratamento foram anestesiados com benzocaína (1,0g/15L de água) e pesados antes da obtenção de amostras de sangue, fígado, intestino anterior e músculo branco. Foram determinadas a taxa de crescimento especifico (TCE), a conversão alimentar (CA), a morfologia da mucosa intestinal, a concentração de metabólitos circulantes e teciduais, a atividade respiratória dos leucócitos (AR... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this study was to evaluate the effect of oral administration of β-glucan on growth, feed utilization, metabolic dynamics and the innate immune responses of pacu (Piaractus mesopotamicus) subjected to short-term starvation and refeeding and the immunostimulatory action of β-glucan offered for 15 days in the final phase of the cycle. A total of 210 fish was distributed in 21 tanks and submitted to different feeding strategies for seven weeks: GC - feeding daily with commercial feed (RC); G 6/1- 6-day feeding with RC and 1 restraint day (6/1); G 2/1 - 2-day feeding with RC and 1 restraint day (2/1); GCS - Feeding daily with RC and supplemented with 0.5% β-glucan (RCS) in the last 15 days; GS 6/1 - 6-day feeding with RC and 1 restraint day, and RCS in the last 15 days; GS 2/1 - 2-day feeding with RC and 1 restraint day, and RCS in the last 15 days. A seventh group (GC-PBS) was fed every day to control the effect of the handling and bacterial inoculation (injected PBS control). On day 50, nine fish of each treatment were sampled, weighed and anaesthetized with benzocaine (1.0g / 15L water) for blood, liver, white muscle and foregut sampling, to determine the specific growth rate (SGR), feed conversion (CA), morphology of intestinal mucosa, concentration of circulating and tissue metabolites, leukocyte respiratory burst, serum lysozyme concentrations, serum hemolytic activity of complement system (alternative pathway), total leukocyte differential count and intest... (Complete abstract click electronic access below) / Doutor

This research work was designed to detect the presence of Aeromonas in the Cocà River estuary, Fortaleza, Cearà State, Brazil. The database consisted of 30 samples of the riverâs surface water and 30 samples of the riverâs sooil, in the period from September, 2007 to April, 2008.. They were amenable, simultaneously, to counting of bacteria on Agar Gelatin Phosphate Salt (GSP) plus 20μg/mL of ampicilim (UFC/mL or UFC/g) The results showed dissemination of Aeromonas in the estuary. The counts for the water samples varied from 10 to 7,050 and from 25 to 38,500 UFC/mL at points A and B respectively; and from 100 to 37,500 UFC/g, and 1,200 to 43500 UFC/g at points A and B respectively. At point C, the counts for water and sediment were smaller than 10 UFC per ml or gram in all samples The occurrence of the greatest indices of Aeromonas in April, at the height of the rainy season, and the lowest in Septemer, at the height of the dry season, suggests there to be a probable seasonality of bacteria density in the studied environment. Among the 41 isolated strains were found the species A. caviae, A. sobria, A. trota, A. salmonicida and A. allossacharophyla. All the strains of Aeromonas sp. were found to be sensitive to cloranfenicol and ceftriaxona except for ampicillim, to which they showed 100% resistance.All the stirps showed resistance to two out of the nine tested antibiotics. After the Curingâ technique, the eritromicina resistance seems to be of plasmidian origin. / Este projeto teve como objetivo principal a pesquisa de Aeromonas spp. em Ãgua de superfÃcie e sedimento em trÃs pontos distintos ao longo do rio CocÃ, CearÃ. Foram realizadas coletas no perÃodo de outubro de 2007 a abril de 2008 gerando um total de 30 amostras de Ãgua e 30 de sedimento. A quantificaÃÃo da comunidade bacteriana pertencente ao gÃnero Aeromonas foi feita atravÃs de plaqueamento direto sobre Agar Gelatina Fosfato Sal (Agar GSP acrescido de 20μg/mL de ampicilina). Nas amostras de Ãgua, os valores obtidos variaram de 10 a 7.050 UFC/mL e de 25 a 38.500 UFC/mL nos pontos A e B, respectivamente. Nas amostras de sedimento, as contagens variaram de 100 a 37500 UFC/g e 1.200 a 43.500 UFC/g nos pontos A e B, respectivamente. Nas amostras de Ãgua e sedimento do ponto C, os valores foram menores que 10 UFC (por mL ou g) em todas as coletas. As maiores contagens foram verificadas no mÃs de abril, perÃodo de chuva, e as menores no mÃs de setembro, perÃodo de estiagem. Foram feitos isolamentos e apÃs identificaÃÃo as estirpes foram submetidas à teste de antibiograma e à tÃcnica da âcuraâ do plasmÃdio. Dentre as 41 cepas isoladas, foram identificadas as espÃcies A. caviae, A. sobria, A. trota, A. salmonicida e A. allossacharophyla. Todas as cepas se mostraram sensÃveis ao cloranfenicol e ceftriaxona. Todas as estirpes apresentaram resistÃncia a, pelo menos, dois dos nove antibiÃticos testados. ApÃs a tÃcnica de cura, a maior parte da resistÃncia a eritromicina ficou caracterizada como de origem plasmidial.Conclui-se que o estuÃrio do Rio Cocà està contaminado por Aeromonas e que muitas delas apresentam resistÃncias a antibiÃticos denotando um ambiente poluÃdo e de risco para a populaÃÃo que usa suas Ãguas para lazer, pesca ou outra atividade qualquer.

Submitted by (edna.saturno@ufrpe.br) on 2016-10-07T13:54:35Z No. of bitstreams: 1 Fernanda Silva de Meirelles.pdf: 599414 bytes, checksum: be09ab548e388263d8d38ab7cabb0cf5 (MD5) / Made available in DSpace on 2016-10-07T13:54:35Z (GMT). No. of bitstreams: 1 Fernanda Silva de Meirelles.pdf: 599414 bytes, checksum: be09ab548e388263d8d38ab7cabb0cf5 (MD5) Previous issue date: 2010-02-26 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / In Brazil, it is considered that the annual production of tilapias overcomes 100 thousand tons, mainly due to the productive potential of the Northeast area that answered for 41% of the total production of 70.000 tons in 2004, generating income of US$ 200.000.000,00, due to your climatic conditions, technology readiness and consumption market, regional and national in expansion. The intensification of cultivations has as consequence the increase of organic matter, that it favors the multiplication of microorganisms, making possible him/it supplies of diseases in the occurrence of adverse situations to the fish. Tilapia (Oerochromis niloticus) of cultivations of the state of Pernambuco they were appraised with objective of determining the frequency of bacterial diseases. For so much, samples of several farms were analyzed, in the several aspects, with relevance for the bacterial agents. The tilapia were examined with relationship to the streptococcus presence, víbrios, coliform, pseudomonas and aeromonas. Clinical exams and autopsy were accomplished, for microscopic analysis of the lesions and better definition of the probable agent etiological. The analyses were accomplished at the Laboratory of Sanity of Aquatic Animals (LASAq) of the Rural Federal University of Pernambuco (UFRPE) and in the Center of Development and Diffusion of Technology in Aquaculture of the State University of Bahia (UNEB). The principal pathological agents were víbrios and aeromonas, that are pathogens responsible opportunists for significant losses, being identified the following species in 46 isolated: V. natriegens (1/46), V. metschnikovii (2/46), V. halioticoli (1/46), V. fischeri (2/46), V. mimicus (23/46), V. diabolicus (1/46), V. furnissi (1/46), V. cholerae o1 (1/46), V. scophthalmi (4/46), V. proteolyticus (3/46), V. argarivorans (1/46), V. ordalii (2/46) and Vibrio spp. ( 3/46). The isolated vibrios presented larger sensibility to the antimicrobianos enrofloxacina (100%) and florfenicol (98,18%) and in decreasing order, gentamicina (90,91%), cotrimoxazol (sulfametoxazol+trimetroprim) (76,36%), tetraciclin (67,27%), eritromicin (30,91%) and amoxilina (3,64%). The isolated ones tested they came 100% resistant the penicillin. In this study, 96,4% (53/55) of the víbrios they presented index multiple resistance to antibiotics (MAR), superior to 0,22, characterizing multiple resistance. In 35 isolated the identified aeromonas were: A.caviae (1/35), A. shubertii (11/35), A. media (4/35), A. popoffii (1/35), A. sobria (3/35), A. encheleia (4/35), A. veronii (4/35) e A. jandaei (4/35) Forty were tested isolated of aeromonas with relationship to the sensibility to 08 antimicrobial, of these they showed larger sensibility the florfenicol (100,0%), enrofloxacina(95,0%), gentamicina (95,0%) and in decreasing order, cotrimoxazol (sulfametoxazol+trimetroprima) (67,5%), tetraciclina (65,0%). There was smaller sensibility the eritromicina (20,0%), penicillin (5,0%) and the amoxilina (2,5%), confirming the resistance existence. The index of multiple resistance to antibiotics (MAR) for the isolated of aeromonas it varied in an interval from 0,12 to 0,62, of these 95% (38/40) they came superior to 0,22 characterizing multiple resistance. Most of the species of isolated víbrios is not considered pathogenic for the fish (environmental), but nevertheless they can represent risk for the health of the tilapia for subject of opportunism and of the consumer, mainly if consumed raw. The isolated and identified movable aeromonas in this study are commonly considered as environmental, however many of the analyzed fish presented compatible symptomatology with the illness caused by these agents opportunists. / No Brasil, estima-se que a produção anual de tilápias supere 100 mil toneladas, principalmente devido ao potencial produtivo da região Nordeste que em 2004 respondeu por 41 % da produção total de 70.000 toneladas, gerando renda de US$ 200.000.000,00, decorrente de suas condições climáticas, disponibilidade de tecnologia e mercado de consumo, regional e nacional em expansão. A intensificação de cultivos tem como conseqüência o aumento de matéria orgânica, que favorece a multiplicação de microrganismos, possibilitando o surto de doenças na ocorrência de situações adversas aos peixes. Tilápias (Oerochromis niloticus) de cultivos do estado de Pernambuco foram avaliadas com objetivo de determinar a freqüência de doenças bacterianas. Para tanto, analisaram-se amostras de diversas fazendas, nos diversos aspectos, com relevância para os agentes bacterianos. As tilápias foram examinadas quanto à presença de estreptococos, víbrios, coliformes, pseudomonas e aeromonas. Foram realizados exames clínicos e necropsias, para análise microscópica das lesões e melhor definição do provável agente etiológico. As análises foram realizadas no Laboratório de Sanidade de Animais Aquáticos (LASAq) da Universidade Federal Rural de Pernambuco (UFRPE) e no Centro de Desenvolvimento e Difusão de Tecnologia em Aqüicultura da Universidade Estadual da Bahia (UNEB). Os principais agentes patológicos foram víbrios e aeromonas, que são patógenos oportunistas responsáveis por perdas significantes, sendo identificadas as seguintes espécies em 46 isolados: Vibrio natriegens (1/46), V. metschnikovii (2/46), V. halioticoli (1/46), V. fischeri (2/46), V. mimicus (23/46), V. diabolicus (1/46), V. furnissi (1/46), V. cholerae O1 (1/46), V. scophthalmi (4/46), V. proteolyticus (3/46), V. argarivorans (1/46), V. ordalii (2/46) e Vibrio spp.(3/46). Os vibrios isolados apresentaram maior sensibilidade aos antimicrobianos enrofloxacina (100%) e florfenicol (98,18%) e em ordem decrescente, gentamicina (90,91%), cotrimoxazol (sulfametoxazol+trimetroprima) (76,36%), tetraciclina (67,27%), eritromicina (30,91%) e amoxilina (3,64%). Os isolados testados apresentaram-se 100% resistentes a penicilina. Neste estudo, 96,4% (53/55) dos víbrios apresentaram índice múltipla resistência a antibióticos (MAR), superior a 0,22, caracterizando múltipla resistência. Em 35 isolados as aeromonas identificadas foram: Aeromonas caviae (1/35), A. shubertii (11/35), A. media (4/35), A. popoffii (1/35), A. sobria (3/35), A. encheleia (4/35), A. veronii (4/35) e A. jandaei (4/35). Foram testados 40 isolados de aeromonas quanto à sensibilidade a oito antimicrobianos, tendo mostrado maior sensibilidade a florfenicol (100,0%), enrofloxacina(95,0%), gentamicina (95,0%), cotrimoxazol (sulfametoxazol+trimetroprima) (67,5%), tetraciclina (65,0%). Houve menor sensibilidade a eritromicina (20,0%), penicilina (5,0%) e a amoxilina (2,5%), confirmando a existência de resistência. O índice MAR para os isolados de aeromonas variou de 0,12 a 0,62, dos quais 95% (38/40) apresentaram índices superiores a 0,22, caracterizando multiresistência. A maioria das espécies de víbrios isoladas não é considerada patogênica para os peixes (ambientais), mas ainda assim podem representar risco para a saúde das tilápias por questão de oportunismo e do consumidor, principalmente se consumido cru. As aeromonas móveis isoladas e identificadas neste estudo são comumente consideradas como ambientais, porém muitos dos peixes analisados apresentaram sintomatologia compatível com a enfermidade causada por estes agentes oportunistas.

Aeromonas são bactérias Gram-negativas aquáticas. Algumas espécies deste gênero são patógenos oportunistas de muitos animais aquáticos e terrestres, inclusive o homem. Vários fatores de virulência, tais como enterotoxinas, hemolisinas e outras enzimas, tem sido associados com a sua patogenicidade. As proteases extracelulares devem ser vistas como importantes enzimas envolvidas na versatilidade metabólica que possibilitam as Aeromonas persistir nos ambientes aquáticos, interagir com outros organismos, e causar doenças. Neste contexto, o objetivo deste trabalho foi avaliar: as diferenças nas atividades de proteases extracelulares e o perfil eletroforético entre espécies e isolados de Aeromonas, a especificidade por substratos de poteases de Aeromonas, e a clonagem e expressão heteróloga da elastase de Aeromonas. Os resultados mostraram que A. hydrophila apresenta maior atividade proteolítica, sem, entretanto exibir diferenças significativas entre isolados clínicos e ambientais. Zimogramas proteolíticos dos isolados de Aeromonas demonstraram diferentes perfis com 0 a 5 bandas, correspondendo a metalo, serino ou outras proteases. Duas proteases (56K Da e 22 KDa) apresentaram atividade sobre um grande espectro de substratos. A atividade caseinolítica de A. hydrophila IBAer 109 mostra um típico comportamento de "quorum sensing", sendo induzida por gelatina e reprimida por glicose, citrato e amônio. O gene da elastatse (ahyB) de A. hydrophila ATCC7966 foi clonado e expresso em E. coli sob controle do promotor lac. O transformante apresentou bandas proteolíticas de 63 e 38 KDa no espaço periplasmático e extracelular, indicando maturação parcial e dificuldade de secreção desta enzima. / Aeromonas are ubiquitous water-borne Gram-negative bacteria. Some species of this genus are opportunistic pathogens of a variety of aquatic and terrestrial animals, including humans. Several virulence determinants, such as enterotoxins, hemolysins and hydrolytic enzymes, have been implicated in their ability to cause diseases. Extracellular proteases may be regarded as important enzymes in the mechanisms that confer the metabolic versatility that allow Aeromonas to persist in aquatic habitats, to interact with other organisms, and to cause diseases. In this context, the objective of this work was to assess the extent of differences in extracellular proteases activity and electrophoretic profiles among Aeromonas strains, the substrate specificity among Aeromonas proteases, and the cloning and heterologous expression of Aeromonas elastase. The results showed that A. hydrophila has the highest proteolytic activity with no significant difference between clinical and environmental isolates. Protease zymograms of Aeromonas isolates showed different profiles with 0 to 5 bands, corresponding to metallo, serine and other proteases. Two proteases (56 KDa and 22 KDa) showed activity against a large spectrum of substrates. Caseinolytic activity of A. hydrophila IBAer 109 showed a typical "quorum sensing" behavior, and was induced by gelatin and repressed by glucose, citrate and ammonium. The elastase gene (ahyB) of A. hydrophila ATCC7966 was cloned and expressed in E. coli under the control of lac promoter. The transformant showed both periplasmic and extracellular proteolytic bands of 63 and 38KDa, indicating partial maturation and secretion difficulties.

Virulent Aeromonas hydrophila (vAh) is a causative agent of motile Aeromonas septicemia (MAS) in catfish. There are limitations in the current therapeutic and preventative strategies against vAh. The pathogenesis of MAS as well as the immune response of catfish to vAh infection are poorly understood. The aim of this study is to: 1) develop a dual live attenuated vaccine against MAS and enteric septicemia of catfish caused by Edwardsiella ictaluri; and 2) evaluate the vAh bacterial load and gene expression patterns in catfish tissues following vAh infection. Previously, six recombinant vAh proteins (outer membrane protein, TonB-dependent receptor, three fimbrial proteins, and an ATPase) were identified to have vaccine efficacy against MAS, and live attenuated E. ictaluri vaccine strain ESC-NDKL1 was identified as an effective vector for expressing vAh antigens. A total of 29 recombinant ESC-NDKL1 strains have been constructed with the integration of one, two, or three genes encoding vAh antigens into the ESC-NDKL1 chromosome. Vaccine efficacy of the constructed strains was evaluated in channel catfish fingerlings. Four recombinant ESC-NDKL1 strains expressing two vAh antigens (ESC-NDKL1::atpase::fimMrfG, ESC-NDKL1::fim::fimMrfG, ESC-NDKL1::tdr::fimMrfG, and ESC-NDKL1::fim::ompA) showed significant protection against MAS with relative percent of survival (RPS) values of 55.72%, 60.18%, 61.74%, and 54.81%. Four triple recombinant ESC-NDKL1 strains (ESC-NDKL1::fimMrfG::ompA::fimA, ESC-NDKL1::atpase::fimMrfG::ompA, ESC-NDKL1::fim::fimMrfG::ompA and ESC-NDKL1::atpase::tdr::fim) showed the best protection with RPS values of 77.93%, 63.18%, 67.74%, and 82.35%. To gain a better understanding of vAh pathogenesis, catfish fingerlings were intraperitoneally injected with vAh strain ML09-119. The anterior kidney, liver, and spleen were collected for determination of vAh distribution and expression of thirteen pro-inflammatory, innate, and adaptive immune-related genes using real-time PCR. Results revealed that vAh spread into catfish tissues within 2 hours and peaked at 12 hours post-infection. vAh infection initiated a strong inflammatory response in catfish tissues. Additionally, our research revealed that surviving catfish were able to develop a primary immune response and possibly generation of memory B cells against MAS. Such information will facilitate the development of vaccines and therapeutic drugs for preventing and treating MAS outbreaks in catfish aquaculture.

Channel catfish farming is the largest aquaculture industry in the U.S., and virulent Aeromonas hydrophila is an important re-emerging bacterial pathogen of farmed catfish. A. hydrophila is ubiquitous in the aquatic environment and causes motile Aeromonas septicemia (MAS) in farmed catfish. A. hydrophila infection is challenging to treat due to rapidly progressive mass mortalities. Although florfenicol has been used in managing outbreaks, acute onset of anorexia, drug cost, and emergence of antimicrobial-resistant strains are significant concerns. Prevention of MAS by vaccination could be a promising approach, but a commercial vaccine is not available. Thus, it is critical to develop effective vaccines against A. hydrophila to prevent losses in the catfish industry. The overall objective of this study is to develop effective live attenuated A. hydrophila vaccines and understand macrophage-A. hydrophila interactions. To achieve this, potential virulence-related genes from T6SS, secretion pathway, tat pathway, and flagellar system were deleted by in-frame, and mutants’ virulence and protection were evaluated in channel catfish. Also, macrophage-A. hydrophila interactions were explored by studying global gene expression to understand macrophage responses to A. hydrophila and A. hydrophila virulence mechanisms

No description available.

Yes / Here, we present the draft genome sequence of Aeromonas caviae strain L12, which shows quorum-sensing activity. The availability of this genome sequence is important to the research of the quorum-sensing regulatory system in this isolate. / High Impact Research Grants from the University of Malaya (A000001-50001; UM-MOHE HIR Grant UM C/625/1/HIR/MOHE/CHAN/14/1, H-50001-A000027)

Yes / Aeromonas hydrophila has emerged worldwide as a human pathogen. Here, we report the draft whole-genome sequence of a freshwater isolate from Malaysia, A. hydrophila strain M062, and its N-acylhomoserine lactone genes are also reported here. / University of Malaya via High-Impact Research Grants (UM C/625/1/HIR/MOHE/CHAN/01, no. A-000001- 50001), and aUM-MOHEHIR grant (UM C/625/1/HIR/MOHE/CHAN/ 14/1, no. H-50001-A000027)

Aeromonas salmonicida ssp. salmonicida est un agent pathogène aquatique causant la furonculose chez les salmonidés, particulièrement les poissons d’élevage. L'antibiothérapie est la méthode couramment utilisée pour traiter cette maladie dans le monde entier. Toutefois, son efficacité est menacée par l’apparition de souches résistantes, voire multirésistantes, aux antibiotiques. L’étude de ces souches bactériennes devient donc nécessaire afin d’identifier les éléments génétiques responsables de ces résistances et comprendre comment ils contribuent à la propagation de l’antibiorésistance. C’est dans cette démarche que se positionne la présente étude qui a pour objectif de caractériser de nouveaux éléments génétiques porteurs de résistances aux antibiotiques chez A. salmonicida ssp. salmonicida à l’aide du séquençage à longues lectures. Plus spécifiquement, au centre de ce projet se trouve la souche SHY16-3432 dont l’étude a permis d’identifier trois nouveaux variants de plasmides nommés pAsa9b, pAsa5-3432 et pRAS3-3432, où ces deux derniers confèrent les résistances aux antibiotiques observées. L’analyse des séquences de ces trois variants a révélé qu’ils se distinguent tous de leur contrepartie classique par leur contenu en éléments génétiques mobiles. Le plasmide pAsa5-3432 possède une nouvelle région de multirésistances composée de plusieurs éléments génétiques mobiles. Celle-ci semble avoir été acquise à la suite d’une recombinaison entre deux plasmides. De son côté, pRAS3-3432 porte un nouvel élément inséré qui a uniquement été identifié chez l’agent pathogène porcin Chlamydia suis. Quant à pAsa9b, il se différencie du plasmide de référence par l’absence d’une séquence d’insertion. Ces découvertes soulignent ainsi l’importance des éléments mobiles sur la plasticité génomique d’A. salmonicida ssp. salmonicida ainsi que sa grande capacité d’interactions avec d’autres bactéries incluant des agents pathogènes animaux. En outre, les données obtenues dans ce projet suggèrent qu’il est nécessaire d’utiliser le séquençage à lectures longues pour caractériser complètement le génome de bactéries au plasmidome complexe comme A. salmonicida ssp. salmonicida. / Aeromonas salmonicida subsp. salmonicida is an aquatic pathogen that causes furunculosis to salmonids, especially in fish farms. Antibiotherapy is a common method used to treat this worldwide disease. Unfortunately, its effectiveness is becoming limited due to the presence of drug-resistant strains and even multidrug-resistance strains of the bacterium. The study of these bacterial strains becomes necessary in order to identify the genetic elements responsible for this resistance and to understand how they contribute to the spread of antibiotic resistance. In this study, we focused on the A. salmonicida subsp. salmonicida strain SHY16-3432 to characterize novel genetic elements conferring resistance to antibiotics using long-read sequencing technologies. It allowed us to identify three novel plasmid variants named pAsa9b, pAsa5-3432 and pRAS3-3432, the latter two being responsible for the observed antibiotic resistance. The sequence analysis of these three variants revealed that they all differ from their classical counterparts through the presence or absence of mobile genetic elements. The plasmid pAsa5-3432 carries a new multi-drug resistance region composed of numerous mobile genetics elements that appears to have been acquired through plasmid recombination. As for pRAS3-3432, it contains a new inserted element that has only been reported in the swine pathogen Chlamydia suis. Lastly, the only variation between pAsa9b and the reference plasmid is the absence of an insertion sequence in pAsa9b. Overall, these discoveries highlight the significant implication of mobile genetics elements in the genomic plasticity of A. salmonicida subsp. salmonicida and suggest that this aquatic bacterium has a high capacity to interact with other bacteria, including animal pathogens. Furthermore, the data obtained suggest that the use of long-read sequencing technologies is required to fully decipher the genome of bacteria possessing complex plasmid repertoire, such as A. salmonicida subsp. salmonicida.