Estrutura genética de Chromis multilineata (Guichenot, 1853) (Perciformes Pomacentridae) na costa NE do Brasil e ilhas oceânicas: evidências de um passado evolutivo instável.

The fauna of Brazilian reef fishes comprises approximately 320 species distributed along the coast of the mainland and islands ocean. Little is known about the levels of connectivity between their populations, but has been given the interest in the relations between the offshore and the islands of the Brazil, in a biogeographical perspective. The oceanic islands Brazilian hosting a considerable number of endemic species, which are locally abundant, and divide a substantial portion of its reef fish fauna with the Western Atlantic. Among the richest families of reef fish in species are Pomacentridae. This study analyzed through analysis of sequences of the mitochondrial DNA control region (D-loop), the standards-breeding population of C. Multilineata in different areas of the NE coast of Brazil, involving both oceanic islands (Fernando de Noronha Archipelago and of St. Peter and St. Paul) and continental shelf (RN and BA). To this aim, partial sequences were used in the region HVR1 of mtDNA (312pb). The population structure and parameters for the estimates of genetic variability, molecular variance (AMOVA), estimation of the index for fixing (FST) and number of migrants were determined. The phylogenetic relationships between the populations were estimated using neighbor-joining (NJ) method. A group of Bayesian analysis was used to verify population structure, according to haplotype frequency of each individual. The genetic variability of populations was extremely high. The populations sampled show moderate genetic structure, with a higher degree of genetic divergence being observed for the sample of the Archipelago of St. Peter and St. Paul. At smaller geographical scale, the sample of Rio Grande do Norte and the Archipelago of Fernando de Noronha do not have genetic differentiation. Three moderately differentiated population groups were identified: a population group (I), formed by the Rio Grande do Norte (I') and the archipelago of Fernando de Noronha (I''), and two other different groups formed by the island population of the archipelago of Saint Peter and St. Paul (II) and Bahia (III). The genetic patterns found suggest that the species has suffered a relatively recent radiation favoring the absence of shared haplotypes. C. multilineata seems to constitute a relatively homogenous population along the West Atlantic coast, with evidence of a moderate population genetic structure in relation to the Archipelago of St. Peter and St. Paul. These data supports the importance of the dispersal larvae by marine current and the interpopulation similarity this species.

Inferências carioevolutivas sobre grupos crípticos de peixes marinhos e estuarinos

Cytogenetic studies have been revealing a great diversity not detected, until then, in several families of fishes. Many of these groups, especially those that exhibit great diversity, like Perciformes and Siluriformes, possess species with difficult morphologic characterization, called cryptic species, commonly detected through karyotypic analyses, which reveals outstanding interespecific variations with relationship to the number and its chromosomal structures. Thus, the present work intends to contribute for the cytogenetic knowledge of marine and brackish fish species, because they peculiar life habits and by lack of cytogenetic data of your genetic aspects. Therefore, cytogenetic studies were developed in a species of Apogonidae (Perciformes), two species of sea catfishes of the family Ariidae (Siluriformes) and brackish fish Paurachenipterus galeatus (Siluriformes, Auchenipteridae), through C banding, Ag-NOR, use of base-specific flourochromes (DAPI and CMA3), as well as FISH (Fluorescent in situ hybridization) using ribosomal DNA probes 5S and 18S. The present results contribute to a better understanding of the processes of differentiation patterns and chromosome evolution in these groups. The use of other approaches (the morphology and molecular tools) will allow a larger understanding of the genetic and biological diversity of the Brazilian ichthyofauna.

Levantamento cariotípico em espécies de peixes marinhos costeiros de fundo arenoso (Osteichthypes, Perciformes)

Cytogenetics analyses in fish are important because they compose a private group among the vertebrates, occupying a central position in the animal evolution. The Perciforms Order, dominant in the marine and freshwater environment, it constitutes a model potentially useful in the genetic evaluation of populations, as well as in the understanding of its evolutionary processes. In spite of this, cytogenetics studies in this great group is scarce, above all for the inhabitants of sandy bottom and pelagics habits. The present work proposed to contribute for the cytogenetic characterization of nine species of fish marine of sandy bottom of the coast of Rio Grande do Norte (Brazil), identifying the evolutionary patterns related to the karyotype in these species and the existence of filogenetics affinities between them and other Perciformes. The animals were collected in the beaches of the Redinha, Ponta Negra and Búzios (Coast of Rio Grande do Norte) and in Saint Peter and Saint Paul Archipelago. Later on they were submitted to the cytogenetics technical that consist of mitotic estimulation, obtaining of mitotics chromosomes, proceeded by techniques of conventional coloration (Giemsa) and chromosomic bands (Ag-RONs and C band). Diploid number and fundamental number equal to 48 were observed in most of the species: Menticirrhus americanus, Ophioscion punctatissimus, Pareques acuminatus (Sciaenidae); Chloroscombrus chrysurus (Carangidae); Echeneis sp. 2 (Echeneidae); Archosargus probatocephalus (Sparidae) and Orthopristis ruber (Haemulidae). Trachinotus goodei (NF=52) (Carangidae) and Echeneis sp. 1 (Echeneidae) (NF=54) presented variation in NF, staying constant a diploid number equal to 48. RONs was situated in pericentromeric position in whole the scianids, and in the species Echeneis sp. 2 (22° pair), O. ruber and A. probatocephalus (1° pair), coinciding with great heterocromatics blocks in M. americanus (1° pair), P. acuminatus (2° pairl) and O. ruber (1° pair). RONs was also located in the telomeric area of the short arm of the 5° and 11° acrocentrics pairs in T. goodei, 4° and 19° pairs of C. chrysurus, 1° pair (sm) of Echeneis sp. 1. The C band detected centromeric blocks in most of the chromosomes of the species of Sciaenidae, Carangidae and Echeneidae, with great blocks in A. probatocephalus (4° pair). Heterocromatic blocks in telomeric areas in submetacentrics of Echeneis sp. 1, and pericentromerics in M. americanus (1° and 8° pairs), O. punctatissimus (1° pair) and P. acuminatus (2° pair) were also observed. It is noticed a marked conservatism cromossomic in the species of the family Scianidae and Haemulidae in what says respect to the number of acrocentrics chromosomes and the location of RONs. Even so it is outstanding the presence of heterocromatinization events during the karyotypic evolution of this family. Already in the families Sparidae and Carangidae, the obtained results reaffirm examples of small variations structural resultants of inversion and translocation Robertsonian, as important mechanisms of diversification karyotipical, as well as a pattern numerical evolutionary conserved, also observed in representatives of Echeneidae of Atlantic in relation to Pacific. The presence of RONs multiple, observed in the species T. goodei and C. chrysurus seems to represent a character derived in the family Carangidae. The results for the species O. ruber and A. probatocephalus suggest the presence of possible geographical or climatic barriers among populations of NE of Brazil in relationship the one of the SE

Caracterização limnológica e determinação da capacidade suporte do reservatório mendubim, (Rio Grande do Norte) para o cultivo de peixes em tanques-rede

The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05° 38 99,0 S 36°55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 μg.L-1, 30,8 μg.L-1 and 5,62 μg.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1%

Determinação da toxicidade aguda e caracterização de risco ambiental do herbicida Roundup (glifosato) sobre três espécies de peixes

Considering their commercial importance, as these are the species of freshwater fish more commercialized in Brazil, their occurence in different kinds of aquatic environments (lakes, rivers and dams) and for being tolerant to a wide range of variation of various physical parameters and chemical water, the fish species Oreochromis niloticus, Cyprinus carpio and Colossoma macropomum were chosen for this study, furthermore, to test the toxicity we used the herbicide Roundup. The fingerlings of tilapia (Oreochromis niloticus), commun carp (Cyprinus carpio) and tambaqui (Colossoma macropomum) were submitted to the herbicide roundup in the following concentrations: 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, 0.0 (control); 13,89; 14,86; 15,83; 16,81 and 17,78 mg.L-1, and 0.0 (control); 18,06; 19,10; 20,14; 21,18 and 22,22 mg.L-1, respectively, three for 96 hours. The LC50 - 96h for O. niloticus, C. carpio and C. macropomum was 21,63, 15,33 and 20,06 mg.L-1 of the herbicide roundup, respectively. The results show that this herbicide is classified as slightly toxic to the three species. The values of dissolved oxygen, pH and temperature recorded in the aquarium control and aquarium experimental of the three fish species have remained without significant variations during the tests, which reduces the possibility of death caused by sudden variations of these parameters during the 96 hours the experiment. The values of LC50 between different species of fish were observed, noting that the species O.niloticus, C. carpio and C. macropomum showed no expressive differences. The values of environmental risk of Roundup were calculated to obtain more stringent parameters in assessing the dangerousness of those on nontargets. The risk of environmental contamination by Roundup for the Nile tilapia, common carp, and tambaqui are low for the lowest application rate (1 L.ha-1) and depths (1.5 and 2.0 m). The dilution of 100%, the highest recommended dose (5 L.ha-1) and depths (1.5 and 2.0 m) the risk is moderate for the three species. The values of the Risk Ratio (QR) were greater than 0,1, indicating that the values of the CAE and LC50 are above acceptable levels and there is a need, this study, a refinement in ecotoxicological tests

Ecomorfologia de dez espécies de peixes marinhos mais abundantes de Galinhos/RN

Ecomorphology is a science based on the idea that morphological differences among species could be associated with distinct biological and environmental pressures suffered by them. These differences can be studied employing morphological and biometric indexes denominated Ecomorphological attributes , representing standards that express characteristics of the individual in relation to its environment, and can be interpreted as indicators of life habits or adaptations suffered due its occupation of different habitats. This work aims to contribute for the knowledge of the ecomorphology of the Brazilian marine ichthyofauna, specifically from Galinhos, located at Rio Grande do Norte state. 10 different species of fish were studied, belonging the families Gerreidae (Eucinostomus argenteus), Haemulidae (Orthopristis ruber,Pomadasyscorvinaeformis,Haemulonaurolineatum,Haemulonplumieri,Haemulonsteindachneri), Lutjanidae (Lutjanus synagris), Paralichthyidae (Syaciummicrurum), Bothidae (Bothus ocellatus) and Tetraodontidae (Sphoeroidestestudineus), which were obtained during five collections, in the period time of September/2004 to April/2005, utilizing three special nets. The ecomorphological study was performed at the laboratory. Eight to ten samples of each fish specie were measured. Fifteen morphological aspects were considered to calculate twelve ecomorphological attributes. Multivariate statistical analysis methods such as Principal Component Analysis (PCA) and Cluster Analysis were done to identify ecmorphological patterns to describe the data set obtained. As results, H.aurolineatumwas the most abundant specie found (23,03%) and S.testudineusthe less one with 0,23%. The 1st Principal component showed variation of 60,03% with influence of the ecomorphological attribute related to body morphology, while the 2nd PC with 23,25% variation had influence of the ecomorphological attribute related to oral morphology. The Cluster Analiysis promoted the identification of three distinct groups Perciformes, Pleuronectiformes and Tetraodontiformes. Based on the obtained data, considering morphological characters differences among the species studied, we suggest that all of them live at the medium (E.argenteus,O.rubber, P.corvinaeformis,H.aurolineatum,H.plumieri,H.steindachneri,L.synagris) and bottom (S.micrurum,B.ocellatus,S.testudineus) region of column water.

Caracterização ecológica dos peixes recifais do Atol das Rocas

The present work was carried out at the Atol das Rocas (3º 51 S; 33º 49 W), the only atoll of the South Atlantic and the first Brazilian marine protected area. It was guided by the following hypothesis: the composition of the fish communities varies in agreement with the position of the pools; in other words, with or without permanent ocean connection. To test the validity of this hypothesis, the fish abundance was estimated in the connected pools (Barretinha/Barreta Falsa) and unconnected ones (Cemiteriozinho/Âncoras), carrying an ecological characterization of the fishes that inhabit these pools. Additionally, the structural complexity of the sampled places was also evaluated intending to verify the variations of the abundance and diversity of fishes in function to this factor. By the fact of this research was being carried out through the limits of a conservation unit, the samples was realized using visual census techniques. The results generated through uni and multivariate analytic techniques allowed the evidence that decisive factor in the density, richness and diversity variations of fishes are linked to the substratum type (Hard / Soft bottom) and not by the fact that the pool are or are not connected permanently to the ocean. In relation to the structural complexity; 58% of the variations in the diversity of fishes were attributed to changes in the structural complexity, while 12% of the variations in the abundance were attributed to the structural complexity

Características limnológicas e estrutura trófica das comunidades de peixes de alguns lagos naturais e artificiais do Rio Grande do Norte

Artificial lakes must differ from natural lakes in important structural and functional aspects that need to be understood so that these ecosystems can be properly managed. The aim of this work was to test the hypothesis that the artificial lakes (impoundments) in the semi-arid region of the Rio Grande do Norte State are more eutrophic and turbid and have different trophic structure when compared to the natural coastal lakes that occur in the humid eastern coast of the State. To test this hypothesis, 10 natural lakes and 8 artificial lakes with about 100 ha were sampled between September and November 2005 for the determination of some limnological variables and the abundance of the main fish species, which were grouped in three trophic guilds: facultative piscivores, facultative planktivores and omnivores. The results show that the artificial lakes had significantly higher concentrations of total nitrogen, total phosphorus, chlorophyll a , total and volatile suspended solids than the natural lakes. Results also show that the values of pH, total alkalinity, electric conductivity, turbidity as well as the coefficient of vertical attenuation of light were significantly higher in the artificial lakes than in the natural lakes. In the artificial lakes, the abundance of facultative planktivores was significantly higher, while the abundance of facultative piscivores significantly lower than in the natural lakes. There was no significant difference in the abundance of omnivorous fish between the two types of lakes. These results suggest that the increase in turbidity together with the other changes in the water quality of the artificial lakes, modifies the trophic structure of the fish communities reducing the importance of piscivores and the length of the food chains

Inventário das espécies de peixes da costa do Estado do Rio Grande do Norte e aspectos zoogeográficos da ictiofauna recifal do Oceano Atlântico

We present a checklist of the shores fishes of the coast of the Rio Grande do Norte state. Species were registered through the specimens collection, underwater records, samples in landings of artisanal fleet and by compilation of data from literature and ichthyologic collections, between January 2004 to 2006. A total of 440 species form 2 classes, 25 orders, 106 families and 253 genus were registered. It is believed that due the great increase of the number of species registered, the ichthyofauna of the coast of this state is reasonably known

Avaliação demográfica, clinico-laboratorial e genética de indivíduos com lupus eritematoso sistêmico e artrite reumatóide residentes em região tropical

The aetiology of autoimmunes disease is multifactorial and involves interactions among environmental, hormonal and genetic factors. Many different genes may contribute to autoimmunes disease susceptibility. The major histocompatibility complex (MHC) genes have been extensively studied, however many non-polymorphic MHC genes have also been reported to contribute to autoimmune diseases susceptibility. The aim of the present study was to evaluate the influence of SLC11A1 gene in systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Ninety-six patients with SLE, 37 with RA and 202 controls enrolled in this case-control study, were evaluated with regard to demographic, genetic, laboratorial and clinical data. SLE mainly affects females in the ratio of 18 women for each man, 88,3% of the patients aged from 15 to 45 years old and it occurs with similar frequency in whites and mulattos. The rate of RA between women and men was 11:1, with 77,1% of the cases occurring from 31 to 60 years. The genetic analysis of the point mutation -236 of the SLC11A1 gene by SSCP did not show significant differences between alleles/genotypes in patients with SLE or RA when compared to controls. The most frequent clinical manifestations in patients with SLE were cutaneous (87%) and joint (84.9%). In patients with RA, the most frequent out-joint clinical manifestation were rheumatoid nodules (13,5%). Antinuclear antibodies were present in 100% of the patients with SLE. There was no significant relation between activity of disease and presence of rheumatoid factor in patients with RA, however 55,6% of patients with active disease presented positive rheumatoid factor. Significant association between alleles/genotypes of point mutation -236 and clinical manifestations was not found

Análise da estabilidade genética de células-tronco mesenquimais humanas

Human multipotent mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells, have become an important and attractive therapeutic tool since they are easily isolated and cultured, have in vitro expansion potential, substantial plasticity and secrete bioactive molecules that exert trophic effects. The human umbilical cord as a cell source for cell therapy will help to avoid several ethical, political, religious and technical issues. One of the main issues with SC lines from different sources, mainly those of embryonic origin, is the possibility of chromosomal alterations and genomic instability during in vitro expansion. Cells isolated from one umbilical cord exhibited a rare balanced paracentric inversion, likely a cytogenetic constitutional alteration, karyotype: 46,XY,inv(3)(p13p25~26). Important genes related to cancer predisposition and others involved in DNA repair are located in 3p25~26. Titanium is an excellent biomaterial for bone-implant integration; however, the use can result in the generation of particulate debris that can accumulate in the tissues adjacent to the prosthesis, in the local bone marrow, in the lymph nodes, liver and spleen. Subsequently may elicit important biological responses that aren´t well studied. In this work, we have studied the genetic stability of MSC isolated from the umbilical cord vein during in vitro expansion, after the cryopreservation, and under different concentrations and time of exposition to titanium microparticles. Cells were isolated, in vitro expanded, demonstrated capacity for osteogenic, adipogenic and chondrogenic differentiation and were evaluated using flow cytometry, so they met the minimum requirements for characterization as MSCs. The cells were expanded under different concentrations and time of exposition to titanium microparticles. The genetic stability of MSCs was assessed by cytogenetic analysis, fluorescence in situ hybridization (FISH) and analysis of micronucleus and other nuclear alterations (CBMN). The cells were able to internalize the titanium microparticles, but MSCs preserve their morphology, differentiation capacity and surface marker expression profiles. Furthermore, there was an increase in the genomic instability after long time of in vitro expansion, and this instability was greater when cells were exposed to high doses of titanium microparticles that induced oxidative stress. It is necessary always assess the risks/ benefits of using titanium in tissue therapy involving MSCs, considering the biosafety of the use of bone regeneration using titanium and MSCs. Even without using titanium, it is important that the therapeutic use of such cells is based on analyzes that ensure quality, security and cellular stability, with the standardization of quality control programs appropriate. In conclusion, it is suggested that cytogenetic analysis, FISH analysis and the micronucleus and other nuclear alterations are carried out in CTMH before implanting in a patient

Estrutura genética populacional de Lutjanus analis cioba e Lutjanus jocu dentão (Lutjanidae) ao longo do litoral brasileiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Processo biotecnológico voltado a produção de estoques poliploides do camarão-branco litopenaeus vannamei (decapoda, penaeidae)

without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming

Mapeamento cromossômico de genes ribossomais em espécies estuarinas da família Gerreidae Identificação de uniformidade cariotípica e sua empregabilidade com fins biotecnológicos - REPROGEN

Perciformes are dominant in the marine environment, characterized as the largest and most diverse fish group. Some families, as Gerreidae, popularly known as silver jennies, carapebas, or mojarras have a high economic potential to marine fish farming, natural explotation and game fishing. Genetic information of these species are of fundamental importance for their management and production. Despite exist over 13,000 marine fish species described, only 2% were cytogenetically analyzed and less than 1% have some reproductive characteristics known. Induced breeding, cytogenetic characterization and cryopreservation of gametes, represent important areas in applied fish studies. In this project cytogenetic analyzes were performed to acess genetic aspects of Gerreidae species, distributed in coastal and estuarine regions of Northeast Brazil. Different methods for identifying chromosomal regions were employed using conventional techniques (Ag-NORs, C-banding), staining with base-specific fluorochromes (DAPI-CMA3), and physical mapping of ribosomal genes 18S and 5S rDNA, through hybridization in situ with fluorescent probes (FISH). The six species analyzed showed remarkable chromosome conservatism. The 18S and 5S ribosomal genes when analyzed in phylogenetic perspective demonstrate varied evolutionary dynamics, suggesting ocurrence of stasis process in some groups and greater dynamism in others. Double FISH with 18S and 5S probes showed both how efficient cytotaxonomic markers in the homogeneous karyotypes of this group of species. The karyotypic pattern identified in addition to the evolutionary aspects of karyotype, are suggestive of existence of low potential of post-zygotic barrier, prompting further research to prospect for artificial interspecific hybridization of these species of commercial importance

Resistotipagem e transferência genética de plasmídios de resistência entre coliformes e vibrios potencialmente patogênicos para o homem isolados de camarão (litopenaeus vannamei) comercializado em Natal-Rio Grande do Norte

Cinquenta amostras de camarão fresco e refrigerado (Litopenaeus vannamei) foram coletadas em diferentes pontos de comercialização na cidade de Natal RN. As amostras foram maceradas em um gral estéril e 25 gramas semeadas em 225mL de APA contendo 1% de NaCl e 25g em 225mL de CL incubadas a 35ºC - 24 horas. O crescimento em APA foi semeado em placas de Ágar TCBS, incubadas a 35ºC-24h para isolamento de Vibrio e Aeromonas. O crescimento do CL foi semeado em Agar EAM, para isolamento de coliformes. Dos 102 isolados, 91 (89,2%) pertenciam ao gênero Vibrio e 11 (10,8%) ao gênero Aeromonas, com predominância de V. cholerae não O1/não O139, V. alginolyticus, V. carchariae e V. parahaemolyticus K- e A. veronii biogrupo sobria , A. jandaei, A. schubertii, A. veronii biogrupo veronii e A. hydrophila. A menor eficiência entre os antimicrobianos foi da AMP (57,8% de resistência) seguida da AMK (29,4%) e TCY (21,6%). As 39 cepas de Vibrio e Aeromonas multirresistentes se distribuíram em 10 perfis distintos, sendo que um revelou cinco marcos (AMP, CHL, NIT, SXT e TCY) em um isolado de V. carchariae de camarão, adquirido em supermercados. O índice MAR, nas 39 cepas variou de 0,28 a 0,42, sugerindo que são de risco na transferência e difusão da resistência na cadeia alimentar. Após a cura plasmidial pelo tratamento com AO de 24 cepas multirresistentes e com resistência intermediária de víbrio e aeromonas escolhidas aleatoriamente, 13 perderam totalmente a resistência e 7 perderam parcialmente, sendo que o maior percentual de perda da resistência ocorreu nas cepas de V. cholerae não O1 e não O139 (6 cepas), se concentrando nos marcos de resistência a AMP (13), AMK (11), TCY(8) e CIP(3). Os resultados da conjugação realizada entre amostras de Vibrio xvi curadas e a E. coli K12C600 demonstraram que 78,5% das culturas de Vibrio testadas revelaram capacidade de transferência para o gene que confere resistência a AMP e 28,5% para a TCY. Dos coliformes, E. coli foi a mais frequente, seguida de Citrobacter spp, isoladas em 40,3% e 27,5% das amostras respectivamente. AMP foi o antimicrobiano menos eficaz, seguido de TCY. As 11 cepas multirresistentes se distribuíram em 9 perfis distintos, um deles constituído de cinco marcos (AMP, NIT, TCY, CHL, SXT), albergados em uma cepa de Klebsiella spp, oriunda de camarão adquirido em supermercado, similar ao resultado obtido em V. carchariae. Conclui-se que, os camarões marinhos frescos e refrigerados, comercializados em Natal-RN evidenciaram contaminação com coliformes, víbrios e aeromonas multirresistentes a antimicrobianos comumente utilizados na terapia médica e veterinária, e que, possivelmente, a transferência de genes de resistência entre bactérias se constitui um sério problema de saúde pública