Perkinsus beihaiensis infecting the oyster Crassostrea rhizophorae under cultivation and in natural stock in Camamu Bay, Bahia, Brazil / Perkinsus beihaiensis infectando a ostra Crassostrea rhizophorae em cultivo e em estoque natural na Baía de Camamu, Bahia, Brasil

This study investigated the infection of Perkinsus beihaiensis (Perkinsozoa) in the oyster Crassostrea rhizophorae, both from a long-line cultivation system and from a nearby intertidal zone of mangrove, both in the state of Bahia, northeastern Brazil. The collections were performed in October and November 2012, and in January 2013. The oysters (n = 300) were measured, examined macroscopically for signs of infection and then submitted to the following laboratory techniques: histology, Ray"s fluid thioglycollate medium assay (RFTM), polymerase chain reaction (PCR) and sequencing, which confirmed the identification of the pathogen. Histological and RFTM analyses showed, respectively, a mean prevalence of 93.3% and of 69%. The infection was usually mild or very mild. There was no significant difference (p > 0.05) between the environments in terms of infection prevalence or severity. This is the first record of P. beihaiensis in the state of Bahia and the second in oysters from Brazil and South America...

Foi investigada a infecção de Perkinsus beihaiensis (Perkinsozoa) na ostra Crassostrea rhizophorae em um sistema de cultivo do tipo espinhel e em um estoque natural de ostras no manguezal adjacente ambos localizados no estado da Bahia, Nordeste do Brasil. As colheitas foram realizadas em outubro e novembro de 2012 e em janeiro de 2013. As ostras (n = 300) foram medidas, examinadas macroscopicamente quanto a sinais da infecção e submetidas às técnicas laboratoriais: histologia, ensaio em meio de cultivo de tioglicolato de Ray (RFTM), reação em cadeia da polimerase (PCR) e sequenciamento, que confirmou a identificação do patógeno. As análises histológicas e o RFTM mostraram, respectivamente, prevalência média de 93,3% e de 69%. A infecção foi geralmente leve ou muito leve. Não houve diferença significativa (p > 0,05) entre os ambientes em termos de prevalência ou severidade da infecção. Este é o primeiro registro de P. beihaiensis no estado da Bahia e o segundo em ostras do Brasil e América do Sul...

Crecimiento y sobrevivencia de Vibrio parahaemolyticus en ostión americano (Crassostrea virginica) almacenado en refrigeración / Growth and survival of total and pathogenic Vibrio parahaemolyticus in American oyster (Crassostrea virginica) under cold storage

Objetivo. Cuantificar las densidades de Vibrio parahaemolyticus en ostión americano (Crassostrea virginica) almacenado en refrigeración. Material y métodos. Se almacenaron 320 ostiones a 7 °C durante nueve días y se determinaron las densidades totales y patogénicas mediante la técnica NMP-PCR. Resultados. Se observaron densidades de V. parahaemolyticus tlh+ en los días 0,3 y 6 de almacenamiento con 1. 134,2.764 y 0.785 log10NMP/g, respectivamente, y en los días 0 y 3 la densidad patogénica trh+ con 0.477 y 0.519 log10NMP/g, respectivamente; las densidades patogénicas tdh+ (0.519 log10NMP/g), tdh+/trh+ (0.519 log10 NMP/g) y tdh+/orf8+ (-0.444 log10NMP/g) se detectaron al tercer día de almacenamiento. Conclusión. Los resultados sugieren que el crecimiento de V. parahaemolyticus y la ocurrencia de genes patogénicos a 7 °C involucran cambios en la expresión génica como una respuesta al estrés por frío. Esto contribuye a la sobrevivencia y virulencia de V. parahaemolyticus, lo cual representa un riesgo a la salud pública.

Objective. To quantify Vibrio parahaemolyticus densities in American oyster (Crassostrea virginica) under cold storage. Materials and methods. 320 oysters were stored at 7°C for nine days and total and pathogenic densities were determined by the NMP-PCR methodology. Results. V. parahaemolyticus tlh+ densities were observed on 0,3, and 6 days of storage at 1.134, 2.764 and 0.785 log10NMP/g, respectively, and pathogenic density trh+ on 0 and 3 days at 0.477 and 0.519 log10NMP/g, respectively; the pathogenic densities tdh+ (0.519 log10NMP/g), tdh+/trh+ (0.519 log10NMP/g), and tdh+orf8+ (-0.444 log10NMP/g) were detected on day 3 of storage. Conclusion.The results suggest that V. parahaemolyticus growth and pathogenic genes occurrence at 7°C involve changes in the genetic expression as a cold shock response, favoring V. parahaemolyticus survival and virulence, representing a health risk.

Occurrence of potentially pathogenic Vibrio in oysters (Crassostrea gigas) and waters from bivalve mollusk cultivations in the South Bay of Santa Catarina

Introduction This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN) g–1 to 2.3 log10 MPN g–1 oyster and from < 0.5 log10 MPN g–1 to 2.1 log10 MPN g–1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL–1 to 1.7 log10MPN·100mL–1 seawater and from < 0.3 log10 MPN·100mL–1 to 2.0 log10 MPN·100mL–1 seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish. .

Multiple enzymatic profiles of Vibrio parahaemolyticus strains isolated from oysters / Multiple enzymatic profiles of Vibrio parahaemolyticus strains isolated from oysters.

The enzymatic characterization of vibrios has been used as a virulence indicator of sanitary interest. The objective of this study was to determine the enzymatic profile of Vibrio parahaemolyticus strains (n=70) isolated from Crassostrea rhizophorae oysters. The strains were examined for the presence of gelatinase (GEL), caseinase (CAS), elastase (ELAS), phospholipase (PHOS), lipase (LIP), amilase (AML) and DNase. All enzymes, except elastase, were detected in more than 60

of the strains. The most recurrent enzymatic profiles were AML + DNase + PHOS + GEL + LIP (n=16; 22.9

) and AML + CAS + DNase + PHOS + GEL + LIP (n=21; 30

). Considering the fact that exoenzyme production by vibrios is closely related to virulence, one must be aware of the bacteriological risk posed to human health by the consumption of raw or undercooked oysters.

Efecto de bacterias probióticas en el cultivo larvario del ostión de placer Crassostrea corteziensis (Bivalvia: Ostreidae)

Effect of probiotic bacteria on survival and growth of Cortez oyster larvae, Crassostrea corteziensis (Bivalvia: Ostreidae). Disease control problems have major constraints in aquaculture production, and the use of probiotics in larviculture is a valid alternative to antibiotics. This study analyzed the effect of probiotic bacteria on survival and final size of Cortez oyster larvae Crassostrea corteziensis. Two different probiotic concentrations were evaluated, 1x10(4) and 1x10(5)CFU/ml of Lactic acid bacteria (strain NS61) isolated from Nodipecten subnodosus, and bacilli isolated from the white leg shrimp, Litopenaeus vannamei (Pseudomonas aeruginosa, strain YC58) and C. corteziensis (Burkholderia cepacia, strain Y021). Bacteria were added directly into culture tanks, starting the bioassays from veliger to pediveliger stages as follows: (1) Control, without probiotics; (2) lactic acid bacteria (Lb); (3) bacilli mix (Mb) in a proportion 1:1. Results showed a higher larval survival with Lb and Mb at a dose of 1x10(4)CFU/ml compared to the control group. Larvae exposed to Mb at 1x10(5)CFU/ml showed higher survival than Lb and control. Larval final size was not significantly increased with the tested probiotics, but larvae treated with Lb at 1x105CFU/ml showed less survival rate than those treated at 1x10(4)CFU/ml. This study showed the beneficial effect of these probiotics, added individually or mixed in C. corteziensis larvae culture. Rev. Biol. Trop. 59 (1): 183-191. Epub 2011 March 01.

El ostión de placer u ostra del Cortés (Crassostrea corteziensis) se considera como una especie con potencial para ser cultivada en gran escala. Sin embargo, al igual que en otros bivalvos, la alta mortalidad que se presenta durante la etapa larvaria y juvenil, es el principal problema que limita el desarrollo del cultivo en el laboratorio. Un método que está ganando aceptación en la acuicultura es el uso de bacterias probióticas para controlar patógenos microbianos. Este estudio analiza el efecto de estas bacterias en la supervivencia y talla final de larvas de ostión de placer Crassostrea corteziensis. Se utilizó una cepa de bacterias ácido lácticas (cepa NS61) aisladas N. subnodosus, así como de bacilos aislados de L. vannamei (Pseudomonas aeruginosa, cepa YC58) y de C. corteziensis (Burkholderia cepacia, cepa Y021). Las cepas se evaluaron por inmersión en cultivos larvarios de C. corteziensis a dos concentraciones diferentes, hasta completar el estadio pediveliger. Los organismos se trataron con bacterias ácido lácticas (Lb), una mezcla de bacilos (Lb) en proporción 1:1 y un grupo control. La concentración de 1x10(4)UFC/ml registró una mayor supervivencia con Lb y Mb respecto al grupo control. La supervivencia con Mb a una concentración de 1x10(5)UFC/ml fue mayor que la del grupo control y del grupo tratado con Lb. Los resultados mostraron que las larvas de C. corteziensis tratadas con probióticos no incrementaron significativamente su talla respecto a las larvas del grupo control. Mientras que las tratadas con Lb a la concentración mayor, 1x10(5)UFC/ml, mostraron una disminución de la supervivencia respecto a las tratadas con 1x10(4)UFC/ml. Este estudio demostró el efecto benéfico de cepas probióticas utilizadas individualmente o en mezcla en el cultivo larvario de C. corteziensis.

Raw oysters can be a risk for infections

The aims of this study were to count and identify sucrose positive and negative vibrios isolated from cultivated Crassostrea rhizophorae oysters during their growing cycle. Every month for 12 months, 10 to 18 oysters were collected for study. Collections occurred at the Center for Studies of Coastal Aquaculture (CSCA), which is associated with the Institute of Marine Science, Labomar, located in Euzebio, Ceará, Brazil. Approximately 150 oysters and their intervalvular liquor were studied. Vibrio Standard Plates Counts (SPC) from oyster meat and their intervalvular liquor varied from 25 to 59,000,000 CFU/g. For most of the 12 months of the oysters' life, it was possible to identify Vibrio parahaemolyticus. Vibrio carchariae was identified in four collections. Among other isolated species, the most important, considering public health risks, was V. vulnificus, although only one strain was confirmed. We concluded that retail purchased oysters should never be eaten raw or undercooked because many species of the genus Vibrio are known to be pathogenic to humans and live naturally on and in shellfish throughout their life cycle.

Calidad microbiológica de la ostra Crassostrea rhizophorae y aguas de extracción estado Sucre Venezuela / Microbiological quality of the oyster Crassostrea rhizophorae and extraction waters Sucre state Venezuela

La ostra Crassostrea rhizophorae es consumida comúnmente en diversas playas del estado Sucre, sin conocer la carga microbiana que éstas presentan. Por tal motivo se evaluó la calidad microbiológica de la misma y de muestras de agua proveniente de tres estaciones del banco natural de Laguna Grande del Obispo, con el propósito de verificar el cumplimiento de los requisitos microbiológicos establecidos por la Legislación Sanitaria Venezolana y la Administración de Alimentos y Drogas de los Estados Unidos (FDA). Se realizaron muestreos mensuales entre agosto 2005 y julio 2006, determinándose el NMP/100 mL de coliformes totales (CT) y coliformes fecales (CF) en muestras de agua, mientras que en los bivalvos se cuantificó el NMP de CT, CF y Escherichia coli (EC) por gramo de ostra, además de la detección de Salmonella spp. Los resultados obtenidos de CT y CF en muestras de agua de las tres estaciones, cumplieron en la mayoría de los meses, con las exigencias permitidas (70 NMP/100 mL de CT y 14 NMP/100 mL de CF). Durante los meses de muestreo y entre las estaciones analizadas, se observaron variaciones considerables en los valores de CF y EC que estuvieron entre 0 y 2,4 × 10(4) NMP/g de ostra. Los límites permitidos de CF y EC (230 NMP/g de ostra) fueron excedidos por los CF en todas las estaciones durante agosto y diciembre 2005, y también en marzo, mayo y junio 2006, mientras que los de EC se excedieron sólo en diciembre 2005, y marzo y mayo 2006. Salmonella spp. fue detectada en la primera y segunda estación para el mes de septiembre 2005, en la tercera estación para el mes de diciembre del mismo año y en la segunda y tercera estación, para los meses de mayo y julio 2006. Los resultados obtenidos reflejan un alto riesgo de consumir estos moluscos sin haber sido previamente sometidos a una depuración.

In beaches of Sucre State commonly the oyster Crassostrea rhizophorae is consumed without knowing the microbial load microbial that may be presenting. For such motive, the microbiology quality of C. rhizophorae and water samples of three stations from natural bank in Laguna Grande of Obispo was evaluated, to check the compliance of microbiological requirements established by the Food and Drugs Administration of United States (FDA) and Sanitary Venezuelan Legislation. Monthly samplings between August 2005 and July 2006 was realized, determining the MPN/100 mL of coliforms totals (TC) and faecal coliforms (FC) in water samples, whereas in bivalves MPN of TC, FC and Escherichia coli (EC) was quantified for gram of oyster, further to detection Salmonella spp. The results obtained of TC and FC, in water samples of the three stations, fulfilled in majority of the months, with the requirements mentioned above. During the months sampling and between analyzed stations, considerable variations was observed in values of FC and EC that were between 0 and 2.4 × 10(4) MPN/g oyster. The limits allowed for FC and EC (230 MPN/g oyster) were exceeded by the FC on all stations during August, December 2005, and also in March, May and June 2006, whereas EC exceded only in December 2005, and March and May 2006. Salmonella spp. was detected on first and second station in September 2005, on the third station for December of the same year, and second and third station for May and July 2006. The obtained results reflect high risk of consuming these mollusks without having being before submitted to depuration.

Vibrios patogênicos em ostras (Crassostrea rhizophorae) servidas em restaurantes no Rio de Janeiro: um alerta para a Saúde Pública / Pathogenic Vibrios in oysters (Crassostrea rhizophorae) served at restaurants in Rio de Janeiro: a public health warning

Avaliaram-se 40 amostras de ostras (Crassostrea rhizophorae) servidas in natura em 15 restaurantes da Cidade do Rio de Janeiro, a fim de investigar a presença de Vibrio spp. As amostras de ostras foram analisadas e submetidas a enriquecimento em água peptonada alcalina adicionada de 1 e 3 por cento de NaCl, incubadas a 37°C por 24 horas. Em seguida, os cultivos foram semeados em agar tiossulfato citrato bile sacarose e as colônias suspeitas foram submetidas à caracterização bioquímica. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus e Vibrio vulnificus representaram as principais espécies (> 60 por cento) isoladas a partir das ostras in natura.

Forty oyster samples (Crassostrea rhizophorae) served raw in 15 restaurants in the city of Rio de Janeiro were evaluated in order to investigate the presence of Vibrio spp. The oyster samples were analyzed and subjected to enrichment in alkaline peptone water with the addition of 1 and 3 percent NaCl and incubated at 37°C for 24 hours. Following this, the cultures were seeded onto thiosulfate citrate bile sucrose agar (TCBS) and the suspected colonies were subjected to biochemical characterization. Vibrio parahaemolyticus, Vibrio carchariae, Vibrio alginolyticus and Vibrio vulnificus were the main species (> 60 percent) isolated from raw oysters.

Aeromonas spp. isolated from oysters (Crassostrea rhizophorea) from a natural oyster bed, Ceará, Brazil

Foram realizadas 30 coletas quinzenais, entre abril e outubro de 2002, de ostras (Crassostrea rhizophorea) de um criadouro natural, no estuário do rio Cocó (Fortaleza/Ceará/Brasil), objetivando-se isolar cepas de Aeromonas spp. As amostras de ostras foram submetidas aos métodos de plaqueamento direto (PD) e presença/ausência (P/A). Foram identificadas Aeromonas em 15 (50%) amostras analisadas pelo método PD e em 13 (43%) pelo método P/A. Foram isoladas: A. caviae, A. eucrenophila, A. media, A. sobria, A. trota, A. veronii bv. sobria, A. veronii bv. veronii e Aeromonas sp. A espécie predominate foi A. veronii (ambos biovars), identificada em 13 (43%) amostras, seguida de A. media em 11 (37%) e A. caviae em 7 (23%). Das 59 cepas identificadas, 28 (48%) apresentaram resistência a pelo menos um, dos oitos antibióticos testados.