Antibacterial Mechanism of Shikonin Against Vibrio vulnificus and Its Healing Potential on Infected Mice with Full-Thickness Excised Skin.

Shikonin has anticancer, anti-inflammatory, and wound healing activities. Vibrio vulnificus is an important marine foodborne pathogen with a high fatality rate and rapid pathogenesis that can infect humans through ingestion and wounds. In this study, the antibacterial activity and possible antibacterial mechanism of shikonin against V. vulnificus were investigated. In addition, the ability of shikonin to control V. vulnificus infection in both pathways was assessed by artificially contaminated oysters and full-thickness excised skin-infected mice. Shikonin treatment can cause abnormal cell membrane function, as evidenced by hyperpolarization of the cell membrane, significant decreased intracellular ATP concentration (p < 0.05), significant increased intracellular reactive oxygen species and malondialdehyde content (p < 0.05), decreased cell membrane integrity, and changes in cell morphology. Shikonin at 40 and 80 µg/mL reduced bacterial numbers in shikonin-contaminated oysters by 3.58 and 2.18 log colony-forming unit (CFU)/mL. Shikonin can promote wound healing in mice infected with V. vulnificus by promoting the formation of granulation tissue, hair follicles, and sebaceous glands, promoting epithelial cell regeneration and epidermal growth factor production. These findings suggest that shikonin has a strong inactivation effect on V. vulnificus and can be used in food production and wound healing to effectively control V. vulnificus and reduce the number of diseases associated with it.

Vibrio ostreae sp. nov., a novel gut bacterium isolated from a Yellow Sea oyster.

A Gram-stain-negative, oxidase- and catalase-positive, facultative anaerobic motile bacterium, designated strain OG9-811T, was isolated from the gut of an oyster collected in the Yellow Sea, Republic of Korea. The strain grew at 10-37 °C, pH 6.0-9.0 and with 0.5-10% (w/v) NaCl. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that strain OG9-811T affiliated with the genus Vibrio, with the highest sequence similarity of 98.2% to Vibrio coralliilyticus ATCC BAA-450T followed by Vibrio variabilis R-40492T (98.0 %), Vibrio hepatarius LMG 20362T (97.7 %) and Vibrio neptunius LMG 20536T (97.6 %); other relatives were Vibrio tritonius JCM 16456T (97.4 %), Vibrio fluvialis NBRC 103150T (97.0 %) and Vibrio furnissii CIP 102972T (97.0 %). The complete genome of strain OG9-811T comprised two chromosomes of a total 4 807 684 bp and the G+C content was 50.2 %. Results of analysis based on the whole genome sequence showed the distinctiveness of strain OG9-811T. The average nucleotide identity (ANI) values between strain OG9-811T and the closest strains V. coralliilyticus ATCC BAA-450T, V. variabilis R-40492T, V. hepatarius LMG 20362T, V. neptunius KCTC 12702T , V. tritonius JCM 16456T, V. fluvialis ATCC 33809T and V. furnissi CIP 102972T were 73.0, 72.6, 73.3, 73.0, 72.7, 78.5 and 77.8 %, respectively, while the digital DNA-DNA hybridization values between strain OG9-811T and the above closely related strains were 20.8, 21.2, 20.8, 21.7, 20.7, 23.2 and 22.4 %, respectively. The major fatty acids of strain OG9-811T were summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) and C16:0. The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Strain OG9-811T contained Q-8 as a quinone. On the basis of polyphasic taxonomic characteristics, strain OG9-811T is considered to represent a novel species, for which the name Vibrio ostreae sp. nov. is proposed. The type strain is OG9-811T (=KCTC 72623T=GDMCC 1.2610T).

Ostreibacterium oceani gen. nov., sp. nov., isolated from oyster, and description of Ostreibacteriaceae fam. nov.

A novel Gram-stain-negative, short rod-shaped, facultatively anaerobic, non-motile, non-gliding, oxidase-positive and catalase-negative bacterium, designated ML27T, was isolated from oyster homogenate in Rushan, Weihai, PR China. Growth occurred at 20-33 °C (optimum, 30 °C), at pH 7.0-9.0 (optimum, pH 7.5-8.0) and in the presence of 1-6 % (w/v) NaCl (optimum, 3 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain ML27T was 90.7 % similar to Suttonella ornithocola DSM 18249T, 89.2 % to Suttonella indologenes JCM 1478T and 88.2 % to Cardiobacterium hominis DSM 8339T; similarities to other species were less than 90 %. The average amino acid identity between strain ML27T, S. indologenes JCM 1478T, S. ornithocola DSM 18249T, C. hominis DSM 8339T and Dichelobacter nodosus ATCC 25549T were 46.23, 45.86, 45.54 and 45.84 %, respectively. Phylogenomic tree and phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate formed a novel family-level clade in the order Cardiobacteriales. The sole respiratory quinone was ubiquinone-7 (Q-7). The dominant cellular fatty acids were summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c; 46.3 %), C16 : 0 (17.8 %) and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c; 13.5 %). The DNA G+C content of strain ML27T was 45.6 mol%. Polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and one unidentified lipid. Comparative analyses of 16S rRNA gene sequences, genomic distinctiveness and characterization indicated that strain ML27T represents a novel species of a new genus within a novel family of the order Cardiobacteriales, for which the name Ostreibacterium oceani gen. nov., sp. nov. is proposed. The type strain of Ostreibacterium oceani is ML27T (=MCCC 1H00372T=KCTC 72155T). In addition, a novel family, Ostreibacteriaceae fam. nov., is proposed to accommodate the genus Ostreibacterium.

Complete genome sequence of the Pseudomonas oleovorans strain ODT-83 isolated from oyster.

A bacterial strain ODT-83 is isolated from oysters, which is capable of adsorbing norovirus (NoV) via histo-blood group antigen-like (HBGA-like) substances. To better understand its genetic background associated with the production of HBGA-like substances, the genome of the ODT-83 was completely sequenced and analyzed. The ODT-83 only contains one circular chromosome, with a length of 5,384,159 bp. Both the 16S rRNA gene phylogeny and the average nucleotide identity (ANI) analyses confirm that the ODT-83 is a new Pseudomonas oleovorans strain. The whole genome encodes a total of 5037 predicted open reading frames (ORFs), 66 tRNA genes and 12 rRNA genes. Two gene clusters are detected on the genome, which are involved in the synthesis of polysaccharides of alginate and Pel, respectively. These results lay the foundation for further research on the interaction between the P. oleovorans strain ODT-83 and NoV.

Effects of the curcumin-mediated photodynamic inactivation on the quality of cooked oysters with Vibrio parahaemolyticus during storage at different temperature.

Photodynamic inactivation (PDI) is a promising method with multiple targets to inactivate bacteria on food using visible light. Inactivation potency of the curcumin-mediated blue light-emitting diode (LED) PDI against the pathogen Vibrio parahaemolyticus on cooked oysters and its effects on the storage quality were investigated by the microbiological, physical, chemical and histological methods during storage at 4 °C, 10 °C and 25 °C. Results showed that the PDI treatment obviously inhibited the recovery of V. parahaemolyticus on oysters during storage, and the maximal difference attained >1.0 Log10 CFU/g (> 90%) compared to control stored at 10 °C and 25 °C. Meanwhile, it displayed a potent ability (p < 0.05) to restrain the decrease of pH values, reduce the production of total volatile basic nitrogen (TVB-N), suppress the lipids oxidation, as well as retard the changes of color difference of the oysters. In addition, the PDI effectively maintained the integrity and initial attachments of muscle fibers, and hence decreased the loss of water in myofibrillar space and the texture softening of oysters during storage. On this basis, this study facilitates the understanding of the potency of bacterial inactivation and food preservation of PDI, and hence pave the way for its application in food industry.

Perfil de resistência da Escherichia coli, isoladas de água e ostras, aos betalactâmicos / Profile resistance of Escherichia coli, isolated from water and oysters, to betalactams

Com o objetivo de avaliar o grau de contaminação por coliformes presentes na água e em ostras e isolar cepas de Escherichia coli para testar seu perfil de resistência aos antibióticos β-lactâmicos, foram coletadas amostras de água e ostras nas regiões de Baixão de Guaí e Capanema, Estuário da Baía do Iguape, BA. A partir das análises microbiológicas de contagem de coliformes à 35ºC e 45ºC, cepas de E. coli foram isoladas e identificadas para realização dos testes de suscetibilidade aos antimicrobianos pertencentes a família dos β-lactâmicos – amoxicilina (10μg), ampicilina (10μg), azetronan (30μg), imipenem (10μg), cefalotina (30μg), ceftriaxona (30μg), oxacilina (1μg), utilizando a técnica de difusão de disco em placas. Foi verificado que todos os isolados apresentaram resistência à oxacilina, em contrapartida 100% das cepas de E. coli avaliadas demonstraram perfil de sensibilidade à azetronam, seguidas por 97% ao imepenem e ceftriaxona e 90% à ampicilina.

Genotypic characterization and assessment of infectivity of human waterborne pathogens recovered from oysters and estuarine waters in Brazil.

Waterborne, food-borne and sewage-borne pathogens are a major global concern, with the annual recurrence, most notably during the summer, of outbreaks of gastroenteritis of unconfirmed etiology associated with recreational activities in marine environments. The consumption of contaminated water-based foodstuffs is also related to outbreaks of human illness. The main goals of the present study were: i) to identify the genetic assemblages of Giardia duodenalis cysts in growing and depurated oysters destined for human consumption on the southern coast of São Paulo, Brazil; ii) to verify the main circulating G. duodenalis assemblages and their subtypes in different brackish waters used for the production of mollusks and for recreational purposes; iii) to track the contamination of growing and depurated oysters by the human adenovirus and identify the infectivity of adenoviral particles recovered from oysters before and after depuration; iv) to evaluate the occurrence and genotype of the free-living amoebae of the genus Acanthamoeba in brackish water and oysters from all the sites described above. Four sampling sites in the Cananeia estuary were selected to search for pathogenic and amphizoic protozoa (Giardia and Acanthamoeba respectively): site 1: oyster growth, site 2: catchment water (before UV depuration procedure), site 3: filter backwash (filtration stage of water treatment) and site 4: oyster depuration tank. Oysters at sites 1 and 4 were evaluated for the presence of adenovirus (HAdV). Analysis consisted of conventional microbiological as well as molecular methods. Giardia duodenalis were detected in all the water sites analyzed and the molecular analysis revealed that sub-assemblage AII was the most frequently distributed throughout the estuarine environment, although one sample was identified as belonging to the assemblage C. Acanthamoeba were also isolated from different locations of the estuarine area, and were detected at all the analyzed sites. The majority of isolates belonged to the T3 genotype, while the T4 genotype was identified once. The sequencing reaction of Giardia duodenalis revealed the contamination of three batches of depurated oysters by the sub-assemblage AII. With respect to viruses, seven batches of oysters (four growing and three depurated) were found to be harboring infectious HAdV particles when submitted to plaque assay. Overall, the results of the sequencing reactions combined with the plaque assay revealed that the isolates of Giardia duodenalis and the infectious HAdV particles identified in oyster tissues have the potential to infect humans and pose a threat if consumed raw or lightly cooked. This is the first report on the sub-assemblage AII identified in oysters which are submitted to a cleaning and disinfection procedure prior to human consumption in Brazil. Acanthamoeba specific genotypes were also identified for the first time in a recreational estuarine area in Brazil, contributing to knowledge of their molecular and environmental epidemiology, which is considered scarce even in marine and estuarine areas of the world.

[Chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster and their in vitro antitumor activity].

Isolation and purification of chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster was performed through silica gel column chromatography, gel filtration over Sephadex LH-20, preparative TLC and HPLC. Five compounds were obtained and their structures were determined as chaetoglobosin V(1), chaetoglobosin Vb(2), tyrosol(3), 5-methyluracil(4)and uracil(5), respectively, based on HR-MS and NMR data and comparison with literatures. In vitro cytotoxicity of compounds against human hepatocellular carcinoma cell line SMMC-7721 were measured byMTT method, and results showed that compound 1 could obviously inhibit the proliferation of SMMC-7721 cells with an IC50 value of 60.5 mg•L⁻¹, while the IC50 value of positive control cisplatin was 19.96 mg•L⁻¹. Further studies discovered that compound 1 could lead to G2 phase arrest in SMMC-7721 cells and induce SMMC-7721 cells apoptosis. The ratio of Bcl-2/Bax in SMMC-7721 cells was decreased. The expression of protein Caspases-3,-8,-9 was improved and the expression and phosphorylation level of Akt were reduced. Aforementioned results revealed that in vitro antitumor activity of compound 1 against SMMC-7721 cells were related to G2 phase cell cycle arrest and induced-apoptosis. The induced-apoptosis was involved in both the mitochondrial pathway and the death receptor pathway and connected with activity decline of PI3K/Akt signaling pathway.

Rare occurrence of heart lesions in Pacific oysters Crassostrea gigas caused by an unknown bacterial infection.

On rare occasions, small cream-coloured cysts have been observed in the heart and pericardial cavity of Pacific oysters Crassostrea gigas from British Columbia, Canada. Histopathology revealed the presence of large colonies of bacteria (up to 800 µm in diameter) causing significant host response and hypertrophy of the heart epithelium. The causative bacteria were characterized as follows: Gram-negative, coccoid to small rod-shaped, typically <1.5 µm in size, cell walls highly endowed with surface fimbriae and division via binary fission. Although these bacteria shared some morphological characteristics with the order Rickettsiales, they did not require an intracellular existence for multiplication. Unfortunately, a cultured isolate was not available, and a retrospective attempt to further characterize the bacteria using DNA sequence analysis of a fragment from the 16S rDNA region proved to be uninformative.

Photodynamic effect of curcumin on Vibrio parahaemolyticus.

Vibrio parahaemolyticus (V. parahaemolyticus) is currently a major cause of bacterial diarrhoea associated with seafood consumption. The objective of this study was to determine the inactivation effect of curcumin-mediated photodynamic action on V. parahaemolyticus. First of all, V. parahaemolyticus suspended in PBS buffer was irradiated by a visible light from a LED light source with an energy density of 3.6J/cm(2). Colony forming units (CFU) were counted and the viability of V. parahaemolyticus cells was calculated after treatment. Singlet oxygen ((1)O2) production after photodynamic action of curcumin was evaluated using 9,10-Anthracenediyl-bis (methylene) dimalonic acid (ADMA). Bacterial outer membrane protein was extracted and analyzed using electrophoresis SDS-PAGE. DNA and RNA of V. parahaemolyticus were also extracted and analyzed using agarose gel electrophoresis after photodynamic treatment. Finally, the efficacy of photodynamic action of curcumin was preliminarily evaluated in the decontamination of V. parahaemolyticus in oyster. Results showed that the viability of V. parahaemolyticus was significantly decreased to non-detectable levels over 6.5-log reductions with the curcumin concentration of 10 and 20µM. Photodynamic action of curcumin significantly increased the singlet oxygen level with the curcumin concentration of 10µM. Notable damage was found to bacterial outer membrane proteins and genetic materials after photodynamic treatment. Photodynamic action of curcumin reduced the number of V. parahaemolyticus contaminating in oyster to non-detectable level. Our findings demonstrated that photodynamic action of curcumin could be a potentially good method to inactivate Vibrio parahaemolyticus contaminating in oyster.

A cytokine-like factor astakine accelerates the hemocyte production in Pacific oyster Crassostrea gigas.

Astakine has been reported to be a hematopoietic growth factor of prokineticin homolog firstly found in arthropods freshwater crayfish Pacifastacus leniusculus. In the present study, an astakine homologous gene was identified from Pacific oyster Crassostrea gigas (designated CgAstakine). The full length cDNA of CgAstakine encoded a polypeptide of 103 amino acids containing a prokineticin (PK) domain homologous to that in astakine from freshwater crayfish P. leniusculus. The deduced amino acid sequence of CgAstakine shared higher similarity with those of other invertebrate astakines than prokineticins from vertebrates. The mRNA of CgAstakine was highly expressed in hepatopancreas and adductor muscle of oyster, while the CgAstakine protein was mainly distributed in hepatopancreas, gill and hemocytes. The mRNA expression of CgAstakine in hemocytes was significantly increased (p < 0.01) and maintained at a high level from 3 h to 9 h after Vibrio anguillarum challenge. After the oyster hemocytes were incubated with 5 µg/mL recombinant CgAstakine protein (rCgAstakine) for 24 h in vitro, the proliferation of hemocytes was significantly increased to 1.89 fold of that in control group (p < 0.05). Moreover, the total count of oyster hemocytes was significantly upregulated (2.45 fold of that in control group, p < 0.05) at 12 h after the oysters were received an injection of rCgAstakine (0.5 µg/g). These results collectively indicated that CgAstakine could modulate the hemocytes proliferation both in vitro and in vivo, and probably involved in the hematopoietic process fighting against the invasion of foreign pathogens.

RAW TROPICAL OYSTERS AS VEHICLES FOR MULTIDRUG-RESISTANT Vibrio parahaemolyticus / Ostras tropicais cruas como fonte de Vibrio parahaemolyticus multirresistentes

The following study aimed to determine the antimicrobial susceptibility profile of Vibrio parahaemolyticus strains from fresh and frozen oysters Crassostrea rhizophorae sold in Fortaleza-Brazil. An antibiogram was performed on 87 isolates using nine antibiotics: gentamicin (Gen 10 µg), ampicillin (Amp 10 µg), penicillin G (Pen 10U), ciprofloxacin (Cip 5 µg), chloramphenicol (Chl 30 µg), nalidixic acid (Nal 30 µg), tetracycline (Tet 30 µg), vancomycin (Van 30 µg) and erythromycin (Ery 15 µg). All strains were resistant to at least one antibiotic, and 85 (97.7%) were multi-resistant, with predominance of the Van+ Pen+Amp resistance profile (n = 46). Plasmid resistance to Pen, Amp and Ery was detected. Thus, the risk that raw oyster consumption poses to the health of consumers is highlighted, due to the fact that these bivalves may host antibacterial-resistant microorganisms.

O presente estudo objetivou determinar o perfil de suscetibilidade a antimicrobianos de cepas de Vibrio parahaemolyticus oriundas de ostras “in natura” e congeladas comercializadas em Fortaleza-Brasil. Oitenta e sete (87) cepas foram submetidas ao antibiograma com emprego de nove antibióticos: gentamicina (Gen 10 µg), ampicilina (Amp 10 µg), penicilina G (Pen 10U), ciprofloxacin (Cip 5 µg), cloranfenicol (Clo 30 µg), ácido nalidíxico (Nal 30 µg), tetraciclina (Tet 30 µg), vancomicina (Van 30 µg) e eritromicina (Eri 15 µg). Todas as cepas mostram-se resistentes a pelo menos um antibiótico, e 85 (97,7%) apresentaram multirresistência, com predomínio do perfil Van+ Pen+Amp (n = 46). Foi detectada resistência plasmidial a Pen, Amp e Eri. Dessa forma, o risco que o consumo de ostras cruas representa para a saúde dos consumidores merece ser destacado, uma vez que esses bivalves podem ser veículos de transmissão de micro organismos multirresistentes a fármacos antibacterianos.

Non-O1, non-O139 Vibrio cholerae bacteraemia in an Australian population.

This retrospective case series identifies the largest cohort of non-O1, non-O139 Vibrio cholerae bacteraemia in an Australian population from 2000 to 2013. We examine the risk factors, epidemiology, clinical presentations and mortality of non-O1, non-O139 V. cholerae bacteraemia in Victoria and compare them with published cases in the literature. This case series highlights the pathogenic potential of non-O1, non-O139 V. cholerae and identifies possible associations with host (underlying chronic liver disease and malignancy) and environmental factors (contaminated water supply and raw seafood). Clinicians should be aware of the morbidity and mortality associated with invasive non-O1, non-O139 V. cholerae infections, particularly in immunocompromised patients.

Description of Tropicibacter mediterraneus sp. nov. and Tropicibacter litoreus sp. nov.

Four strains (M15∅_3, M17(T), M49 and R37(T)) were isolated from Mediterranean seawater at Malvarrosa beach, Valencia, Spain. Together with an older preserved isolate (strain 2OM6) from cultured oysters at Vinaroz, Castellón, Spain, the strains were thoroughly characterized in a polyphasic study and were placed phylogenetically within the Roseobacter clade in the family Rhodobacteraceae. Highest 16S rRNA sequence similarities of the five strains to the types of any established species corresponded to Tropicibacter multivorans (95.8-96.4%), Phaeobacter inhibens (95.9-96.3%) and Phaeobacter gallaeciensis (95.9-96.2%). On the other hand, whole genome (ANI) and protein fingerprinting (MALDI-TOF) data proved: (i) non clonality among the strains, and (ii) the existence of two genospecies, one consisting of strains M15∅_3, M17(T), M49 and 2OM6 and another one consisting of strain R37(T). Phenotypic traits determined allow differentiating both genospecies from each other and from closely related taxa. In view of all data collected we propose to accommodate these isolates in two species as members of the genus Tropicibacter, Tropicibacter mediterraneus sp. nov. (type strain M17(T)=CECT 7615(T)=KCTC 23058(T)) and Tropicibacter litoreus sp. nov. (type strain R37(T)=CECT 7639(T)=KCTC 23353(T)).

Health assessment of the oyster Crassostrea rhizophorae on the southern coast of Bahia, northeastern Brazil / Avaliação da saúde da ostra Crassostrea rhizophorae no litoral sul da Bahia, nordeste do Brasil

This study investigated the health of natural stocks of the oyster Crassostrea rhizophorae on the southern coast of Bahia in northeastern Brazil, during summer and winter 2010, at three localities (sampling points) in the estuaries of the Maraú (Camamu Bay) and Graciosa rivers. A total of 180 oysters (30/sampling point/season) were examined macroscopically for the presence of pathogens and anatomical changes. The specimens were subsequently fixed in Davidson solution, processed for paraffin embedding, sectioned and stained with Harris' hematoxylin and eosin. Histological analysis revealed the presence of Rickettsia-like organisms (RLOs), Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus in the sporocyst phase, a nonspecific metacercaria, and a metacestode of genus Tylocephalum. The prevalence of infection was low except for parasitism by Nematopsis sp. which also caused histopathological changes. The presence of Bucephalus sp. caused parasitic castration. These two pathogens significantly affect the health of C. rhizophorae.

Este estudo investigou a saúde de ostras da espécie Crassostrea rhizophorae de estoques naturais do Litoral Sul do Estado da Bahia, Nordeste do Brasil, durante o verão e o inverno de 2010, em três pontos amostrais distribuídos nos estuários dos rios Maraú (Baía de Camamu) e Graciosa. Um total de 180 ostras (30/ponto amostral/período) foram examinadas macroscopicamente para a presença de patógenos e alterações anatômicas e posteriormente fixadas em solução de Davidson, processadas para inclusão em parafina, seccionadas e coradas com hematoxilina de Harris e eosina. A análise histológica evidenciou a presença de organismos com características similares a Rickettsia (RLOs), Ancistrocoma, Trichodina, Sphenophrya, Nematopsis, Urastoma, Bucephalus em fase esporocística, metacercária inespecífica e metacestóide de Tylocephalum. As prevalências de infecção foram baixas, com exceção do parasitismo por Nematopsis sp., o qual também causou alterações histopatológicas. A presença de Bucephalus sp. causou castração parasitária. Esses dois patógenos têm interferência significativa na saúde de C. rhizophorae.

Hemolytic and urease activities in vibrios isolated from fresh and frozen oysters

INTRODUCTION: The present study aimed to survey the Vibrio microbiota of oysters (Crassostrea rhizophorae) obtained from restaurants in Fortaleza, State of Ceará, Brazil, and to identify virulence factors. METHODS: The isolated vibrios were submitted to biochemical identification and were tested for hemolytic and urease activities. RESULTS: The isolated strains belonged to 13 species, with predominance of Vibrio mimicus. Of the strain isolates only from fresh samples, 20.5% and 2.8% showed hemolytic and urease activities, respectively. CONCLUSIONS: The findings support the little-publicized claim that Vibrio species other than V. parahaemolyticus and V. vulnificus can represent a health risk to public health.

Evaluation of tropical water sources and mollusks in southern Brazil using microbiological, biochemical, and chemical parameters.

Florianópolis, a city located in the Santa Catarina State in southern Brazil, is the national leading producer of bivalve mollusks. The quality of bivalve mollusks is closely related to the sanitary conditions of surrounding waters where they are cultivated. Presently, cultivation areas receive large amounts of effluents derived mainly from treated and non-treated domestic, rural, and urban sewage. This contributes to the contamination of mollusks with trace metals, pesticides, other organic compounds, and human pathogens such as viruses, bacteria, and protozoan. The aim of this study was to perform a thorough diagnosis of the shellfish growing areas in Florianópolis, on the coast of Santa Catarina. The contamination levels of seawater, sediments, and oysters were evaluated for their microbiological, biochemical, and chemical parameters at five sea sites in Florianópolis, namely three regular oyster cultivation areas (Sites 1, 2, and oyster supplier), a polluted site (Site 3), and a heavily polluted site (Site 4). Samples were evaluated at day zero and after 14 days. Seawater and sediment samples were collected just once, at the end of the experiment. Antioxidant defenses, which may occur in contaminated environments in response to the increased production of reactive oxygen species (ROS) by organisms, were analyzed in oysters, as well as organic compounds (in oysters and sediment samples) and microbiological contamination (in oysters and seawater samples). The results showed the presence of the following contaminants: fecal coliforms in seawater samples (four sites), human adenovirus (all sites), human noroviruses GI and GII (two sites), Hepatitis A viruses (one site), JC Polyomavirus in an oyster sample from the oyster supplier, Giardia duodenalis cysts, and Cryptosporidium sp oocysts (one site). Among organochlorine pesticides, only DDT (dichlorodiphenyltrichloroethane) and HCH (hexachlorocyclohexane) were detected in some sediment and oysters samples in very low levels; site 4 had the highest concentrations of total aliphatic hydrocarbons, PAHs, and linear alkylbenzenes (LABs) found either in oysters or in sediment samples. The major concentration of fecal sterol coprostanol was found at site 4, followed by site 3. After 14 days of allocation in the four selected sites, there was a significant difference in the enzymes analyzed at the monitored spots. The detection of different contaminants in oysters, seawater, and sediment samples in the present study shows the impact untreated or inadequately treated effluents have on coastal areas. These results highlight the need for public investment in adequate wastewater treatment and adequate treatment of oysters, ensuring safe areas for shellfish production as well as healthier bivalve mollusks for consumption.

Characterization of Vibrio Parahaemolyticus isolated from oysters and mussels in São Paulo, Brazil / Caracterização de Vibrio parahaemolyticus isolados de ostras e mexilhões em São Paulo, Brasil

Vibrio parahaemolyticus is a marine bacterium, responsible for gastroenteritis in humans. Most of the clinical isolates produce thermostable direct hemolysin (TDH) and TDH-related hemolysin (TRH) encoded by tdh and trh genes respectively. In this study, twenty-three V. parahaemolyticus, previously isolated from oysters and mussels were analyzed by PCR using specific primers for the 16S rRNA and virulence genes (tdh, trh and tlh) and for resistance to different classes of antibiotics and PFGE. Nineteen isolates were confirmed by PCR as V. parahaemolyticus. The tlh gene was present in 100 percent of isolates, the tdh gene was identified in two (10.5 percent) isolates, whereas the gene trh was not detected. Each isolate was resistant to at least one of the nine antimicrobials tested. Additionally, all isolates possessed the blaTEM-116 gene. The presence of this gene in V. parahaemolyticus indicates the possibility of spreading this gene in the environment. Atypical strains of V. parahaemolyticus were also detected in this study.

Vibrio parahaemolyticus é uma bactéria marinha, responsável por gastroenterite em humanos. A maioria dos isolados clínicos produzem hemolisina termoestável direta (TDH) e hemolisina TDH-relacionada (TRH) codificadas por genes tdh e trh, respectivamente. Neste estudo, vinte e três V. parahaemolyticus, previamente isolados de ostras e mexilhões foram analisados por PCR utilizando indicadores específicos para o gene 16S rRNA, genes de virulência (tdh, trh e tlh), resistência a diferentes classes de antibióticos, e PFGE. Dezenove isolados foram confirmados por PCR, como V. parahaemolyticus. O gene tlh estava presente em 100 por cento dos isolados, o gene tdh foi identificado em dois (10,5 por cento) dos isolados, enquanto que o gene trh não foi detectado. Cada isolado foi resistente a pelo menos um dos nove antibióticos testados. Além disso, todos os isolados apresentaram resultado positivo para o gene blaTEM-116. A presença deste gene em V. parahaemolyticus indica a possibilidade de propagação desse gene no ambiente. Cepas atípicas de V. parahaemolyticus foram também detectadas neste estudo.

Effects of combined treatment of sodium hypochlorite/ionizing radiation and addition of vitamin B(1) on microbial flora of oyster and short-necked clam.

To determine the synergistic disinfection effect of the combined treatments of sodium hypochlorite (NaClO), irradiation, and vitamin B(1), the bactericidal effects of the treatments on natural microflora of oyster and short-necked clam were investigated. Then, bacteria isolated from the samples were identified by 16S rDNA sequencing. Oyster and short-necked clam were mainly contaminated with Vibrio spp. and Bacillus spp. Total number of aerobic bacteria ranged from 10(2) to 10(4) colony forming units (CFU)/g initially. More than 100 mg/L of NaClO with 1000 mg/L vitamin B(1) and 2 kGy irradiation treatment for oyster and short-necked clam can reduce the total aerobic bacteria to the level of lower than a detection limit (10 CFU/g). Synergistic effects were observed for all combined treatment against natural microflora. The results suggest that a significant synergistic benefit can be achieved by a combination of NaClO-ionizing radiation treatment with the addition of vitamin B(1) to reduce the microbial population contaminated in oyster and short-necked clam.

An unusual case of sepsis with both Vibrio vulnificus and Enterococcus casseliflavus.

An 87-year-old man with metastatic prostate cancer on prior dexamethasone and chemotherapy presented to the emergency department with fever, hypotension and diarrhea. Blood cultures at the time of admission revealed both Vibrio vulnificus and Enterococcus casseliflavus. Raw oysters harvested from a Louisiana marsh were consumed 12 and 13 days pre-admission. V. vulnificus sepsis typically manifests within one to three days of exposure, though prior reports have indicated infections as late as seven days later. These bacteria particularly grow in warmer saline waters, and infections are less common in winter. Warming trends in US weather and in particular warming trends in the coastal marshes where oysters are grown and harvested may create less seasonal variation and higher rates of Vibrio infection.