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.

Características de Vibrio parahaemolyticus isolados de mexilhões (Perna perna) comercializados em Niterói, Rio de Janeiro / Characteristics of Vibrio parahaemolyticus isolated from mussels (Perna perna) commercialized at Niterói, Rio de Janeiro

O ecossistema marinho é o habitat natural de bactérias como Vibrio parahaemolyticus, um importante patógeno causador de gastrenterite humana associada ao consumo de alimentos marinhos. Na presente investigação, foi avaliada a presença de V. parahaemolyticus a partir de 86 amostras de mexilhões in natura e pré-cozidos. Vibrio parahaemolyticus foi isolado a partir de 11,6 por cento dos mexilhões in natura e pré-cozidos avaliados. Todas as cepas avaliadas demonstraram-se urease positivas e 28,5 por cento Kanagawa positivas sugerindo um potencial patogênico para o homem. Houve a predominância do sorotipo O10:K52 e a identificação da cepa emergente O3:K6. Esses resultados apontam para a relevância epidemiológica de V. parahaemolyticus em casos de gastrenterite humana após consumo de mexilhões sem cozimento adequado (100°C/15min). Além disso, é importante alertar as autoridades de Vigilância Sanitária no Brasil quanto a sua presença na cadeia alimentar e seus riscos para a Saúde Pública.

The marine ecosystem is the natural habitat of bacteria like Vibrio parahaemolyticus, an important pathogen that cause human gastroenteritis associated with seafood consumption. In the present investigation, the presence of V. parahaemolyticus in 86 in natura and precooked mussel samples was evaluated. Vibrio parahaemolyticus was isolated from 11.6 percent of the in natura and precooked mussels. All strains tested were urease-positive and 28.5 percent were Kanagawa-positive, which suggests that they have pathogenic potential for humans. There was predominance of the O10:K52 serotype and the emerging O3:K6 strain was identified. These results show the epidemiological relevance of V. parahaemolyticus in cases of human gastroenteritis following mussel consumption without adequately cooking them (100°C/15min). Moreover, it is important to alert the Brazilian Sanitary Surveillance authorities regarding their presence in the food chain and their public health risks.

Characterization of vibrio parahaemolyticus isolated from coastal seawater in peninsular Malaysia.

Twenty-one Vibrio parahaemolyticus isolates representing 21 samples of coastal seawater from three beaches in peninsular Malaysia were found to be sensitive to streptomycin, norfloxacin and chloramphenicol. Resistance was observed to penicillin (100%), ampicillin (95.2%), carbenicilin (95.2%), erythromycin (95.2%), bacitracin (71.4%), cephalothin (28.6%), moxalactam (28.6%), kanamycin (19.1%), tetracycline (14.3%), nalidixic acid (9.5%) and gentamicin (9.5%). Plasmids of 2.6 to 35.8 mDa were detected among plasmid-containing isolates. All isolates carried the Vp-toxR gene specific to V. parahaemolyticus and were negative for the tdh gene, but only one isolate was positive for the trh gene. DNA fingerprinting of the isolates using ERIC-PCR and PFGE showed that the isolates belong to two major clonal groups, with several isolates from different locations in the same group, indicating the presence of similar strains in the different locations.

Revisión y recomendaciones para el manejo de diarrea por Vibrio parahaemolyticus / Review and guidelines for treatment of diarrhea caused by Vibrio parahaemolyticus

A contar del año 1998 se han presentado en Chile tres brotes epidémicos por Vibrio parahaemolyticus, el último de ellos durante el verano del 2005, que afectó a más de 10.000 personas. Los afectados presentaron un cuadro clínico caracterizado por diarrea, náuseas, vómitos, dolor abdominal y fiebre; 6 por ciento de los casos tuvo leucocitos fecales positivos y un paciente falleció. La cepa predominante en los tres brotes ha sido la pandémica O3: K6. El diagnóstico de V. parahaemolyticus se realizó con la confirmación microbiológica de las cepas y tipificación o por asociación epidemiológica. Las cepas fueron susceptibles in vitro a tetraciclina, cefalosporinas de tercera generación, quinolonas y cloranfenicol no observándose susceptibilidad a ampicilina. Todos los casos se asociaron al consumo de mariscos crudos o insuficientemente cocidos. Por la repercusión de este brote, el Ministerio de Salud impulsó la formación de una comisión multidisciplinaria para actualizar los aspectos epidemiológicos, clínicos y microbiológicos, y elaborar una guía de recomendaciones en el manejo de esta infección.

Potentiality of a new compound for in vitro differentiation between halophilic and non-halophilic vibrios.

Sensitivity of 21 halophilic vibrios and 16 clinical isolates of non-halophilic vibrios was determined against a new possible antivibrio agent, a pyrimidine analogue, 4, 6-dimethylpyrimidine -2-thiol (4,6-DMPT). It appeared to be a vibriocidal agent, having a mean MIC and MBC of 32 microg/ml for halophilic strains and 64 microg/ml for non-halophilic strains and an LD50 of 300 mg/Kg body weight of mice. Thus, 4,6-DMPT may help an in vitro distinction between halophilic and non-halophilic vibrios. Sensitivity of these strains was also studied with respect to pteridine, crystal violet and Tween 80 hydrolysis as further markers distinguishing between these 2 groups which could also be differentiated by their growth on TCBS or/and CLED media.

Characterization of the pili isolated from Vibrio parahaemolyticus O3:K6.

Pilus of Vibrio parahaemolyticus O3:K6 strain LVP9 belonging to the newly identified clone was purified and characterized. The molecular mass of the pilin was estimated to be about 18 kDa by SDS-PAGE, and the isoelectric point of the pilin was 5.0 +/- 0.2. The LVP9 pili were antigenically different from the other V. parahaemolyticus Na2 pili and Ha7 pili as previously reported, nevertheless all three had indistinguishable morphology and shared a high degree of homology in their N-terminal amino acid sequences. Strain LVP9 and its purified pili did not agglutinate human and rabbit erythrocytes. The LVP9 organisms and the purified pili were adhesive to the rabbit intestine. The adhesion was inhibited by pretreatment of the rabbit intestine with the purified pili or by pretreatment of the organisms with the Fab fractions of anti-pilus antibody. These results indicate that the LVP9 pilus is an adherent factor to the rabbit intestine.

Enumeração e identificação de Vibrio parahaemolyticus em lulas frescas comercializadas no município de Niterói RJ Brasil / Enumeration and identification of Vibrio parahaemolyticus in fresh squids commercialized at Niterói, Rio de Janeiro State, Brazil

Com o objetivo de verificar as condições higiênico-sanitárias do pescado comercializado no município de Niterói, efetuou-se um estudo sobre a enumeração e identificação de Vibrio parahaemolyticus em lulas frescas. Foram utilizadas 50 amostras de lulas frescas, identificadas como pertencentes à espécie Oorytheutis brasiliensís Blainville, 1823. A identificação e enumeração do V. parahaemolyticus foram baseadas nos métodos descritos pela lnternational Commission on Microbiological Specifications for Foods - ICMSF (1983). A classificação de Heiberg (1936) foi utilizada como teste complementar. O V. parahaemolyticus foi identificado em três (6%) amostras, sendo que, em uma o vibrio se desenvolveu em meio com concentração salina a 10%, na prova de halofilismo. O V. parahaemolyticus apresentou os NMPs (Número Mais Provável) com média de 19,3.bactérias/g. As três amostras de V. parahaemolyticus submetidas à classificação de Heiberg apresentaram perfil compatível com o grupo VIl (Sacarose -, Manose + e Arabinose +). Concluiu-se que, mesmo sob comercialização inadequada, com manipulação e resfriamento precários, as amostras analisadas apresentaram o V. parahaemolyticus com frequências e NMPs baixos.

A study on the enumeration and identification of Vibrio parahaemolyticus in freshsquids in Niterói was undertook aiming at checking the hygienic-sanitary conditions of fish commercialized in that City. Fifty fresh squids (Oorytheutis brasiliensis, Blainville, 1823). Methods described by the lnternational Comission on Microbiological Specification for Foods-ICMSF (1983) were used to identify and enumerate V. parahaemoiyticus and Heiberg's classi-fication was a complementai test. v. parahaemoiyticus was identified in three samples (6%); in one of them it grew in an environment with 10% salt concentration during halophilism probe. Most probable number (MPN) average for V. parahaemoiyticus was 19,3 bacteria per gram. The three samples submitted to Heiberg's classification showed a profile compatible with group VIl (sacarose-, manose+, arabinose-). We concluded that, even under inadequate commercialization, manipulation and refrigeration conditions, V. parahaemolyticus frequencies and MPNs are low.

Caracterizaçäo sorológica de amostras de Vibrio Parahaemolyticus isoladas de peixes capturados no litoral brasileiro / Serological characterization of strains of Vibrio parahaemolyticus isolated from fishis caugth off the Brazilian coast

Em 82 peixes de origem marinha e de diferentes espécies, capturados na faixa de litoral compreendida entre Bahia e Rio Grande do Sul, foram detectados 45 ou 54, 8 por cento portadores de Vibrio parahaemolyticus, propiciando o isolamento de 71 culturas. Na caracterizaçäo sorológica (0: K), 13 sorotipos foram identificados (24 ou 33, 7 por cento) e 47 ou 66, 1 por cento das amostras só permitiram o reconhecimento da estrutura "O".os sorotipos mais incidentes foram: 02: k28; 05: K17; 01: 32 e 02: K12; nos grupos sorológicos predominaram 02; 04; 05 e 03. Näo foi evidenciado qualquer vínculo de espécies de peixes com determinados sorotipos ou sorogrupos tampouco, os níveis de isolamento sofreram a influência da sszonalidade.