RESUMO

The geographical distribution of Bathoxiphus ensiculus (Jeffreys, 1877) and Cadulus platensis Henderson, 1920 is greatly extended based on new records, the former being registered for the first time in the southwestern Atlantic. The type materials of both species are figured and an updated diagnosis of Bathoxiphus Pilsbry & Sharp, 1897 is presented. A new deep-sea species of Cadulus is described, Cadulus victori sp. nov., known from only empty shells collected in the Northeast Brazil (off Alagoas and Bahia states) and distinguished from his congeners mainly by the strongly inflated shell, general outline and dimensions. The present study reinforces that although recent taxonomic revisions have been performed on the Scaphopoda from the southwestern Atlantic, there are still unknown or unrecorded species in museum collections, mostly from poorly sampled areas, especially in the deep sea.

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RESUMO

The geographical distribution of Bathoxiphus ensiculus (Jeffreys, 1877) and Cadulus platensis Henderson, 1920 is greatly extended based on new records, the former being registered for the first time in the southwestern Atlantic. The type materials of both species are figured and an updated diagnosis of Bathoxiphus Pilsbry & Sharp, 1897 is presented. A new deep-sea species of Cadulus is described, Cadulus victori sp. nov., known from only empty shells collected in the Northeast Brazil (off Alagoas and Bahia states) and distinguished from his congeners mainly by the strongly inflated shell, general outline and dimensions. The present study reinforces that although recent taxonomic revisions have been performed on the Scaphopoda from the southwestern Atlantic, there are still unknown or unrecorded species in museum collections, mostly from poorly sampled areas, especially in the deep sea.(AU)

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RESUMO

The aim of this study was to determine the serogroups, antimicrobial resistance and genetic diversity of Escherichia coli isolates from samples of bivalve mollusks collected along Santa Catarina coast, Brazil, and from the Chesapeake Bay, Maryland, USA. One hundred forty-one E. coli isolates were characterized for serogroups with 181 specific O antisera and antimicrobial susceptibility using the disk diffusion method. The genetic diversity was assessed using pulsed-field gel electrophoresis (PFGE). The results showed that among the isolates, 19.9% were classified as multi-drug resistant (MDR) and resistance was most frequently observed to cephalothin, nitrofurantoin, and ampicillin. The predominant serogroups were O6, O8, and O38. Some serogroups were recognized as pathogenic E. coli. PFGE dendrograms indicated extensive genetic diversity among the isolates. Although characteristics of the E. coli isolates were highly variable, it is important to note that E. coli belonging to pathogenic serogroups and MDR isolates are present in mollusks of both study areas. This is the first report on the phenotypic and genotypic characterization of E. coli from mollusks from Santa Catarina and the Chesapeake Bay that should encourage studies focusing on comparison of isolates across countries.

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Since the foundation of the Malacological Center in 1980, Universidad Centro Americana (UCA), Managua-Nicaragua, has been monitoring and collecting the marine, terrestrial, fluvial and lake mollusk population of the country. Many specimens have been photographed by Scanning Electronic Microscope (SEM), and in one of these, observation of the hairy periostracum reveals a seemingly thriving population of minute protists in possible symbiosis with their host. Adequate magnification and comparison with previous studies allowed the determination of these hosts as diatoms, testaceous amoebae, yeast, phacus, spores and other undetermined organisms which occur in tropical forests on rocks, trees and leaves. Here illustrated are diatoms and other organisms detected for the first time on the periostracum of a tropical rainforest mollusk.(AU)

Desde a fundação do Centro Malacológico em 1980, a Universidad Central Americana (UCA), Manágua-Nicarágua, vem acompanhando e coletando a população de moluscos marinhos, terrestres, fluviais e lagoas do país. Muitos espécimes foram fotografados pelo microscópio eletrônico de varredura (SEM) e, em um deles, a observação do periostracum peludo revela uma população aparentemente próspera de protistas de minuto em possível simbiose com o hospedeiro. A ampliação adequada e a comparação com estudos anteriores permitem a determinação dessas diatomáceas, amebas testaceas, leveduras, phacus, esporos e outros organismos indeterminados que ocorrem em florestas tropicais em rochas, árvores e folhas. Aqui estão as diatomeas e outros organismos pela primeira vez detectados no periostracum de um molusco tropical.(AU)

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The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumers health.(AU)

O isolamento de Escherichia coli a partir de alimentos é uma grande preocupação, pois cepas patogênicas desta bactéria podem causar desde diarreia até síndrome hemolítico-urêmica. Diante do exposto, o objetivo do trabalho foi pesquisar genes de virulência em isolados de Escherichia coli provenientes do sururu Mytella guyanensis comercializado na cidade de Cachoeira, Bahia, Brasil. As amostras foram adquiridas de quatro comerciantes, sendo duas de mercados e duas em pontos de venda na feira livre da cidade de Cachoeira, acondicionadas em caixas isotérmicas com gelo reutilizável e transportadas até o laboratório para a análise. Após a análise microbiológica, as cepas de Escherichia coli foram isoladas em ágar Eosina Azul de Metileno e preservadas em caldo Brian Heart Infusion e glicerol a 15% e mantidas a - 20° C. A identificação dos genes de virulência nas cepas isoladas foi realizada utilizando primers específicos, por meio da Reação em Cadeia da Polimerase. Foram obtidos 24 isolados de Escherichia coli, destes a prevalência do gene elt , característico de Escherichia coli enterotoxigênica, foi de 75% dos isolados. Não houve a detecção dos genes stx e bfpA nos isolados, os quais são prevalentes nas cepas de Escherichia coli enterohemorrágica e Escherichia coli enteropatogênica, respectivamente. A presença do gene elt relacionado à virulência de Escherichia coli nos isolados de Mytella guyanensis revela a necessidade da melhoria no processamento, incluindo boas práticas de manipulação, armazenamento adequado e cocção previa ao consumo, visando a garantia da saúde do consumidor.(AU)

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A preocupação com a qualidade do pescado é de grande importância para todos, pois é um alimento de alto valor nutritivo, mas tem grande susceptibilidade à deterioração e formação de substâncias prejudiciais à saúde, quando as condições de conservação e manipulação não são mantidas. O cultivo de moluscos bivalves além de ser uma fonte alternativa de alimentos, é uma opção para a subsistência das populações ribeirinhas de todo o litoral, à medida que a matriz alimentícia ganha espaço no mercado, principalmente nas regiões nordeste, sul e sudeste. Os sururus são organismos filtradores, capazes de absorver micropartículas em suspensão, as quais podem carrear elevadas concentrações de microrganismos patogênicos, outro fator importante relacionado a este molusco é a má condição de manipulação no beneficiamento, que pode provocar toxinfecções alimentares, ambos provocando danos à saúde. As análises microbiológicas foram realizadas em sururu in natura e após cozimento. Nas amostras analisadas houve ausência de Salmonella spp., com redução na contagem de Staphylococcus coagulase-positiva e de Coliformes Termotolerantes a 45ºC nos produtos cozidos. Os resultados são indicativos de que mesmo havendo redução de contaminação bacteriana, a manipulação das catadoras, após cozimento, é inadequada e que medidas corretivas devem ser adotadas para se obter o produto adequado bacteriologicamente ao consumo.

Fish quality has a great importance concerning to its high nutritional value, due to its great susceptibility to deterioration and occurrence of harmful substances to human health when the storage and handling conditions are not kept properly. The bivalves farming is an alternative source of food and also a source of livelihood for riverside communities, as the product is accepted in the market, mainly in the Northeast, South and Southeast regions. As filter feeders organisms, “sururu” mussels can absorb microparticles which can carry high level of pathogenic micro-organisms. Another important factor is the bad handling conditions both can lead to foodstuff infections. Microbiological analyzes were performed in raw “sururu” mussel and after cooking. The samples analyzed there was no Salmonella sp., a reduction in coagulase-positive Staphylococcus count and thermotolerant coliforms at 45 °C in baked products. Results of the analyzes showed that even with the contamination reduction, the handling of the women staff after cooking is inadequate and corrective measures should be taken to obtain a safe product for the final consumer.

Assuntos

RESUMO

A preocupação com a qualidade do pescado é de grande importância para todos, pois é um alimento de alto valor nutritivo, mas tem grande susceptibilidade à deterioração e formação de substâncias prejudiciais à saúde, quando as condições de conservação e manipulação não são mantidas. O cultivo de moluscos bivalves além de ser uma fonte alternativa de alimentos, é uma opção para a subsistência das populações ribeirinhas de todo o litoral, à medida que a matriz alimentícia ganha espaço no mercado, principalmente nas regiões nordeste, sul e sudeste. Os sururus são organismos filtradores, capazes de absorver micropartículas em suspensão, as quais podem carrear elevadas concentrações de microrganismos patogênicos, outro fator importante relacionado a este molusco é a má condição de manipulação no beneficiamento, que pode provocar toxinfecções alimentares, ambos provocando danos à saúde. As análises microbiológicas foram realizadas em sururu in natura e após cozimento. Nas amostras analisadas houve ausência de Salmonella spp., com redução na contagem de Staphylococcus coagulase-positiva e de Coliformes Termotolerantes a 45ºC nos produtos cozidos. Os resultados são indicativos de que mesmo havendo redução de contaminação bacteriana, a manipulação das catadoras, após cozimento, é inadequada e que medidas corretivas devem ser adotadas para se obter o produto adequado bacteriologicamente ao consumo.(AU)

Fish quality has a great importance concerning to its high nutritional value, due to its great susceptibility to deterioration and occurrence of harmful substances to human health when the storage and handling conditions are not kept properly. The bivalves farming is an alternative source of food and also a source of livelihood for riverside communities, as the product is accepted in the market, mainly in the Northeast, South and Southeast regions. As filter feeders organisms, “sururu” mussels can absorb microparticles which can carry high level of pathogenic micro-organisms. Another important factor is the bad handling conditions both can lead to foodstuff infections. Microbiological analyzes were performed in raw “sururu” mussel and after cooking. The samples analyzed there was no Salmonella sp., a reduction in coagulase-positive Staphylococcus count and thermotolerant coliforms at 45 °C in baked products. Results of the analyzes showed that even with the contamination reduction, the handling of the women staff after cooking is inadequate and corrective measures should be taken to obtain a safe product for the final consumer.(AU)

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Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (<50 mm2 or >1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve shells. This study demonstrates how bacterial biofilms may influence sclerobiont colonization on biological hosts (mollusks), and shows how ecological relationships in marine organisms may be relevant for interpreting the fossil record of sclerobionts.

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The bacterial species, Vibrio parahaemolyticus and Vibrio vulnificus, are ubiquitous in estuaries and coastal waters throughout the world, but they also happen to be important human pathogens. They are concentrated by filter-feeding shellfish which are often consumed raw or undercooked, providing an important potential route of entry for an infective dose of these bacteria. Vibrio parahaemolyticus can cause abdominal cramping, nausea, diarrhoea, vomiting, chills and fever. Vibrio vulnificus can cause similar gastrointestinal-related symptoms, but can also spread to the bloodstream, resulting in primary septicaemia, and it can also cause disease via wound infections. The objective of this article is to summarize, for the first time, the incidence and importance of V. parahaemolyticus and V. vulnificus in South America, in environmental waters and seafood, especifically molluscan shellfish, as well as human infection cases and outbreaks. It appears that infections from V. parahaemolyticus have been more strongly related to shellfish ingestion and have been more frequently reported on the Pacific coast of South America. Conversely, V. vulnificus has been more frequently acquired by water contact with open wounds and its presence has been more heavily reported along the Atlantic coast of South America, and while documented to cause serious mortality, have been relatively few in number. The impacts of El Nino Southern Oscillation (ENSO) have been observed to cause an increase in V. parahaemolyticus outbreaks on the Pacific coast of South America. The implementation of a regulated monitoring approach, along with the use of faster, more accurate and virulence-specific detection approaches, such as PCR confirmation, should be considered to detect the presence of pathogenic Vibrio strains in environmental and seafood samples for protection of public health. Furthermore, improved clinical surveillance with suspected cases should be implemented. This review highlights the need for more research and monitoring of vibrios in South America, in water, shellfish and clinical samples.

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El consumo de moluscos bivalvos ha sido asociado con infecciones microbianas aún en casos donde los mismos cumplen con los parámetros de calidad bacteriológica. El proceso de depuración se realiza con el fin de eliminar, de forma natural, los microorganismos presentes en moluscos bivalvos, los cuales han sido acumulados por su proceso de filtración. En este estudio se determinó la tasa de depuración de indicadores potenciales de contaminación. Se realizaron cuatro experimentos con la almeja Polymesoda solida, la cual poseía niveles altos de índices contaminantes de forma natural. Para evaluar el proceso de depuración se utilizaron como indicadores bacterianos los coliformes totales (CT), coliformes fecales (CF), estreptococos fecales (SF), enterococos (EN) y bacterias aerobias mesófilas (AM). El contenido inorgánico total (CIT) se utilizó como indicador del contenido de arena. La desinfección del agua marina, preparada artificialmente, se realizó irradiando con luz UV durante 48 h. El proceso de depuración se realizó durante 120 horas (5 días) a 28°C y 5 UPS, en tanques de 150 L de capacidad. La tasa de remoción bacteriana y física en Polymesoda solida fue más eficiente (80 por ciento) durante las primeras 72 h, alcanzando una calidad bacteriológica y física adecuada para el consumo, sin importar que los ejemplares fueron recolectados de sitios que no cumplían con los niveles aceptables de calidad.

The consumption of shellfish has been associated with microbial infections even in cases where shellfish complied with the current regulation, which is based on bacterial analysis. Depuration processes try to eliminate microorganisms using seawater to allow living, filter-feeding shellfish to naturally purge themselves from agents they accumulated from the environment. In this study, depuration rates of potential indicators were estimated. Four experiments, with naturally-contaminated shellfish (Polymesoda solida), were performed. For evaluating the shellfish depuration process, total coliforms (TC), fecal coliforms (FC), fecal streptococcus (FS), enterococcus (EN) and mesophilic aerobic bacteria (MAB) were evaluated as bacterial indicators. Total inorganic content was used as physical indicator. Artificial prepared seawater of the depuration tank was disinfected by UV irradiation. Depuration removal rates of experiments running for 120 hours (five days) at 28°C, 5 psu, in a 150 L tanks were effective (80 percent) and more efficient during the first 72 hours, allowing an adequate bacterial and physical quality for consumption after this time, no matter the clams were collected in contaminated areas which do not complain with maximal allowable level.

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