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Marc Heyndrickx - One of the best experts on this subject based on the ideXlab platform.
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Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar
Journal of applied microbiology, 2016Co-Authors: Fien Calliauw, Benjamin Horemans, Katrien Broekaert, Chris W. Michiels, Marc HeyndrickxAbstract:Aims During a previous study concerning brown shrimp (Crangon crangon), selective streptomycin thallous acetate actidione (STAA) agar was used to determine the growth of Brochothrix thermosphacta. However, the growth of Vagococcus salmoninarum on this medium was also noticed. This study explores the spoilage potential of this organism when inoculated on sterile shrimp. Methods and Results Isolates growing on STAA were identified using (GTG)5 clustering followed by partial 16S rRNA gene sequence analysis. Their biochemical spoilage potential was analysed for H2S production and enzymatic activities were tested using an APIZYM test. Headspace solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to analyse the volatile organic compounds (VOCs) produced during storage of inoculated shrimp. Conclusion Fifty-five per cent of isolates taken from STAA could be identified as V. salmoninarum, while no apparent morphological difference with B. thermosphacta isolates was identified upon the prescribed incubation conditions. For isolates identified as V. salmoninarum, production of 2-heptanone, 2-nonanone, 2-undecanone was found, as was the possibility to form H2S. Significance and impact of the Study When using the STAA medium for detecting B. thermosphacta, one should consider the possible abundant presence of V. salmoninarum as well. Based on this study, V. salmoninarum does not exhibit great spoilage potential, although it can produce H2S and formed VOCs which are also found in other spoiled seafood products.
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assessment throughout a whole fishing year of the dominant microbiota of peeled brown shrimp crangon crangon stored for 7 days under modified atmosphere packaging at 4 c without preservatives
Food Microbiology, 2016Co-Authors: Fien Calliauw, Katrien Broekaert, Chris W. Michiels, Thijs De Mulder, Geertrui Vlaemynck, Marc HeyndrickxAbstract:Abstract This study was performed to comprehensively reveal the composition of the microbial community of commercially cooked and machine peeled brown shrimp ( Crangon crangon ), packaged and stored under modified atmosphere without added preservatives. Three independent experiments, using both culture-dependent and culture-independent methods, were conducted over an entire shrimp season. Initial total aerobic psychrotrophic bacterial counts (APC) were relatively high on several general media ranging between 5.4 and 6.4 log cfu g −1 . After 7 days of storage at 4 °C, samples were considered microbiologically spoiled with no apparent difference in APC between samples from different periods. The dominant microbiota present after 7 days of storage was assessed by (GTG) 5 analysis of selected colonies and 16S rRNA gene sequence analysis. The dominant organism on general media was Arthrobacter bergerei , whereas on more selective media Shewanella putrefaciens , Brochothrix thermosphacta and Vagococcus salmoninarum were most abundant. Culture-independent denaturant gradient gel electrophoresis (DGGE) and Illumina next generation sequencing revealed Carnobacterium as a dominant genus at day 7 throughout the year, together with members of Shewanella and Psychrobacter . The differences in relative abundance of dominant genera between different months also indicated a possible seasonal influence on the microbial community. It could be concluded that the same major groups of spoilage bacteria were retrieved by culture dependent and independent approaches, but their relative abundance differed.
Fien Calliauw - One of the best experts on this subject based on the ideXlab platform.
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Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar
Journal of applied microbiology, 2016Co-Authors: Fien Calliauw, Benjamin Horemans, Katrien Broekaert, Chris W. Michiels, Marc HeyndrickxAbstract:Aims During a previous study concerning brown shrimp (Crangon crangon), selective streptomycin thallous acetate actidione (STAA) agar was used to determine the growth of Brochothrix thermosphacta. However, the growth of Vagococcus salmoninarum on this medium was also noticed. This study explores the spoilage potential of this organism when inoculated on sterile shrimp. Methods and Results Isolates growing on STAA were identified using (GTG)5 clustering followed by partial 16S rRNA gene sequence analysis. Their biochemical spoilage potential was analysed for H2S production and enzymatic activities were tested using an APIZYM test. Headspace solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to analyse the volatile organic compounds (VOCs) produced during storage of inoculated shrimp. Conclusion Fifty-five per cent of isolates taken from STAA could be identified as V. salmoninarum, while no apparent morphological difference with B. thermosphacta isolates was identified upon the prescribed incubation conditions. For isolates identified as V. salmoninarum, production of 2-heptanone, 2-nonanone, 2-undecanone was found, as was the possibility to form H2S. Significance and impact of the Study When using the STAA medium for detecting B. thermosphacta, one should consider the possible abundant presence of V. salmoninarum as well. Based on this study, V. salmoninarum does not exhibit great spoilage potential, although it can produce H2S and formed VOCs which are also found in other spoiled seafood products.
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assessment throughout a whole fishing year of the dominant microbiota of peeled brown shrimp crangon crangon stored for 7 days under modified atmosphere packaging at 4 c without preservatives
Food Microbiology, 2016Co-Authors: Fien Calliauw, Katrien Broekaert, Chris W. Michiels, Thijs De Mulder, Geertrui Vlaemynck, Marc HeyndrickxAbstract:Abstract This study was performed to comprehensively reveal the composition of the microbial community of commercially cooked and machine peeled brown shrimp ( Crangon crangon ), packaged and stored under modified atmosphere without added preservatives. Three independent experiments, using both culture-dependent and culture-independent methods, were conducted over an entire shrimp season. Initial total aerobic psychrotrophic bacterial counts (APC) were relatively high on several general media ranging between 5.4 and 6.4 log cfu g −1 . After 7 days of storage at 4 °C, samples were considered microbiologically spoiled with no apparent difference in APC between samples from different periods. The dominant microbiota present after 7 days of storage was assessed by (GTG) 5 analysis of selected colonies and 16S rRNA gene sequence analysis. The dominant organism on general media was Arthrobacter bergerei , whereas on more selective media Shewanella putrefaciens , Brochothrix thermosphacta and Vagococcus salmoninarum were most abundant. Culture-independent denaturant gradient gel electrophoresis (DGGE) and Illumina next generation sequencing revealed Carnobacterium as a dominant genus at day 7 throughout the year, together with members of Shewanella and Psychrobacter . The differences in relative abundance of dominant genera between different months also indicated a possible seasonal influence on the microbial community. It could be concluded that the same major groups of spoilage bacteria were retrieved by culture dependent and independent approaches, but their relative abundance differed.
Jean-jacques Joffraud - One of the best experts on this subject based on the ideXlab platform.
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characterisation of the spoilage microbiota in raw salmon salmo salar steaks stored under vacuum or modified atmosphere packaging combining conventional methods and pcr ttge
Food Microbiology, 2012Co-Authors: Sabrina Mace, Mireille Cardinal, Josiane Corne, Frederique Chevalie, Mariefrance Pile, Xavie Dousse, Jean-jacques JoffraudAbstract:Abstract In order to characterise the spoilage related to microbiota of raw salmon, a combination of culture-dependent and -independent methods, including PCR–TTGE, was used to analyse 3 raw salmon batches stored for 3 days at chilled temperature in modified atmosphere packaging (MAP) (50% CO 2 /50% N 2 ) or under vacuum. Sensory evaluation, microbiological enumeration and chemical analysis were performed after 3, 7 and 10 days of storage. At the onset of spoilage, 65 bacterial isolates were picked from the plates. Thus, 13 different genera or species were identified by phenotypic and molecular tests: Serratia spp., Photobacterium phosphoreum , Yersinia intermedia , Hafnia alvei , Buttiauxella gaviniae , Pseudomonas sp., Carnobacterium maltaromaticum , Carnobacterium divergens , Lactococcus piscium , Lactobacillus fuchuensis , Vagococcus carniphilus , Leuconostoc gasicomitatum and Brochothrix thermosphacta. The PCR–TTGE profiles and band identification enabled a shift of the dominant populations during the storage to be visualised for all the batches, probably due to the temperature change and the packaging. At the beginning of storage, Pseudomonas sp. dominated the raw salmon microbiota while in the following days (7 and 10), P. phosphoreum and L. piscium were identified as the main bacterial groups. This study enhances the knowledge of MAP and vacuum-packed raw salmon spoilage microbiota.
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sensory characteristics of spoilage and volatile compounds associated with bacteria isolated from cooked and peeled tropical shrimps using spme gc ms analysis
International Journal of Food Microbiology, 2011Co-Authors: Josiane Cornet, Mireille Cardinal, Xavier Dousset, Emmanuel Jaffres, Valerie Lalanne, Sabrina Mace, Thierry Sérot, Jean-jacques JoffraudAbstract:Abstract The spoilage potential of six bacterial species isolated from cooked and peeled tropical shrimps ( Brochothrix thermosphacta , Serratia liquefaciens -like, Carnobacterium maltaromaticum , Carnobacterium divergens , Carnobacterium alterfunditum -like and Vagococcus penaei sp. nov.) was evaluated. The bacteria were inoculated into shrimps, packaged in a modified atmosphere and stored for 27 days at 8 °C. Twice a week, microbial growth, as well as chemical and sensory changes, were monitored during the storage period. The bacteria mainly involved in shrimp spoilage were B. thermosphacta , S. liquefaciens -like and C. maltaromaticum whose main characteristic odours were cheese-sour, cabbage-amine and cheese-sour-butter, respectively. The volatile fraction of the inoculated shrimp samples was analysed by solid-phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (GC–MS). This method showed that the characteristic odours were most likely induced by the production of volatile compounds such as 3-methyl-1-butanal, 2,3-butanedione, 2-methyl-1-butanal, 2,3-heptanedione and trimethylamine.
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Vagococcus penaei sp. nov., isolated from spoilage microbiota of cooked shrimp (Penaeus vannamei).
International Journal of Systematic and Evolutionary Microbiology, 2010Co-Authors: Emmanuel Jaffres, Jean-jacques Joffraud, Hervé Prévost, Albert Rossero, Xavier DoussetAbstract:A polyphasic taxonomic study, using phenotypic, phylogenetic and genotypic characterization, was performed on five Gram-stain-positive, catalase-negative, coccus-shaped Vagococcus-like bacteria isolated from the spoilage microbiota of cooked shrimp. Comparative 16S rRNA gene sequence analysis indicated that the isolates belonged to the genus Vagococcus. The five isolates shared 100% 16S rRNA gene sequence similarity, and representative strain CD276T formed a branch that was distinct from the type strains of the six recognized species of the genus Vagococcus (Vagococcus fluvialis CCUG 32704T, V. salmoninarum NCFB 2777T, V. lutrae CCUG 39187T, V. fessus M2661/98/1T, V. carniphilus ATCC BAA-340T and V. elongatus PPC9T). The taxonomic position of strain CD276T was clarified using DNA–DNA hybridization, pulsed-field gel electrophoresis of whole-genome DNA, G+C content determination, cell-wall peptidoglycan typing, fatty acid analysis and biochemical characterization. On the basis of this evidence, a novel species, Vagococcus penaei sp. nov., is proposed. The type strain is CD276T (=LMG 24833T =CIP 109914T).
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study of the bacterial ecosystem in tropical cooked and peeled shrimps using a polyphasic approach
International Journal of Food Microbiology, 2009Co-Authors: Francoise Leroi, Emmanuel Jaffres, Jean-jacques Joffraud, Hervé Prévost, Daniele Sohier, Mariefrance Pilet, Xavier DoussetAbstract:Abstract The characterization of the microbial ecosystem of cooked tropical shrimps was carried out using a polyphasic approach. First, culture-dependent methods were used for bacterial enumeration and the phenotypic and molecular identification of bacterial isolates. Then, culture-independent methods, including PCR-TTGE (V3 region of the 16S rRNA gene), provided a fingerprinting of bacterial DNA directly extracted from shrimps. Two batches of cooked and peeled tropical shrimps were stored at 5 and 15 °C for 5 and 3 weeks, respectively. Trained panelists carried out a sensory evaluation and microbiological enumerations were performed. When spoilage of samples was perceived, several colonies were isolated from the total viable count media. Thus, 137 bacterial strains were identified by phenotypic and molecular tests. Lactic acid bacteria (LAB) constituted the major group with the most represented genera being Carnobacterium ( C. divergens , C. maltaromaticum and indiscernible C. alterfunditum/pleistocenium ), Vagococcus (indiscernible V. carniphilus/fluvialis ) and Enterococcus ( E. faecalis and E. faecium ). The other groups corresponded to Brochothrix thermosphacta and Enterobacteriaceae ( Serratia liquefaciens ). In PCR-TTGE profiles some of DNA fragments were assigned to those of standard strains ( S. liquefaciens , B. thermosphacta , E. faecalis , C. divergens and C. maltaromaticum ) or identified isolates from culture-dependent analysis ( E. faecium ). Other additional informations were provided by fragment cloning ( Psychrobacter sp, Citrobacter gillenii and Firmicute ). In conclusion, TTGE is an excellent tool to monitor the evolution of the microbial ecosystem in seafood products.
F Real - One of the best experts on this subject based on the ideXlab platform.
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the in vitro immunomodulatory effect of extracellular products ecps of Vagococcus fluvialis l21 on european sea bass dicentrarchus labrax leucocytes
Fish & Shellfish Immunology, 2015Co-Authors: L Roman, Daniel Padilla, J Bravo, F Acosta, J Vega, El F Aamri, B Vega, E Rodriguez, S Deniz, F RealAbstract:The immune associated genes, interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-α (TNF-α), ciclo-oxigenase-2 (COX-2), and Mx gene were studied by real-time PCR in head-kidney leucocytes of sea bass after incubation with the extracellular products (ECPs) of the probiotic strain Vagococcus fluvialis L21 and polyinosinic:polycytidylic acid (POLY I:C), at different times (T1.5, T6, T12, T24, T48 and T72). In general, we can observe how pro-inflammatory cytokines IL-1β, TNF-α, IL-6 and COX-2 studied displayed a strong peak after stimulation with 1.5 h of ECPs of V. fluvialis L21, significant differences (P < 0.05) exist with other periods and with the POLY I: C at the same time. Similarly to the case of IL-10 also produced a statistically significant (P < 0.05) peak of expression on leukocytes that were stimulated with the ECPs of V. fluvialis L21. In the case of Mx gene expression, we note that in almost all sampling times there is an up-regulation of the Mx gene in leucocytes incubated with ECPs and POLY I:C compared to the control and Mx expression was higher in leucocytes that were stimulated with the ECPs of V. fluvialis for all times, except in T24. With these results we can consider that the ECPs of V. fluvialis L21 have a great power of stimulating the in vitro expression of immune-related genes and may even be useful as adjuvants for vaccine in aquaculture.
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the in vitro effect of probiotic Vagococcus fluvialis on the innate immune parameters of sparus aurata and dicentrarchus labrax
Fish & Shellfish Immunology, 2012Co-Authors: L Roman, F Real, L Sorroza, Daniel Padilla, B Acosta, V Grasso, J Bravo, F AcostaAbstract:Abstract In this study we evaluated the effect of the probiotic Vagococcus fluvialis on the cellular immune unspecific system of two different fish species of great interest in aquaculture such as gilthead sea bream ( Sparus aurata ) and European sea bass ( Dicentrarchus labrax ). Leucocytes from head kidney of the two fish species were extracted and concentration adjusted to 10 7 cells ml −1 . Phagocytic and respiratory burst activity and the peroxidase content of leucocytes were observed 30 min after incubation with the probiotic Vagococcus fluvialis alive or inactivated with heat shock or UV-light at different concentrations of 10 7 , 10 8 , 10 9 cfu ml −1 (final concentration 10 6 , 10 7 , 10 8 cfu ml −1 ). V. fluvialis produced dose-dependent increments in respiratory burst in sea bream leucocytes. The respiratory burst activity of sea bream head kidney leucocytes incubated with 10 6 cfu ml −1 of live and inactivated bacteria was not stimulated. The highest values of peroxidase content were observed in sea bass cells with stimulation indexes higher than 1 in HK leucocytes incubated with 10 8 cfu ml −1 of live and inactivated bacteria. Statistical analysis revealed that differences being only significant in sea bass leucocytes where 10 8 cfu ml −1 bacteria denote statistically significant differences ( P in vitro assays are a useful tool to optimize the effective dose of probiotic bacteria. Although in vivo studies are necessary to confirm the immunomodulatory effect of this strain.
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characterization of the probiotic strain Vagococcus fluvialis in the protection of european sea bass dicentrarchus labrax against vibriosis by vibrio anguillarum
Veterinary Microbiology, 2012Co-Authors: L Sorroza, L Roman, Daniel Padilla, V Grasso, F Acosta, J Vega, F RealAbstract:Aquaculture is one of the main sources of income in many countries worldwide. Intensive farms are often affected by different infectious diseases that can decrease their final production. To control this situation, several antibiotics are frequently used with known environmental consequences. The aim of this study was to analyze different bacterial strains isolated from of gilthead sea bream, sea bass, sole and meagre guts, for use as probiotics in aquaculture. The strains were evaluated in vitro through various mechanisms of selection, such as the production of antagonistic effects against pathogens, production of antibacterial substance, adhesion to the intestinal mucus, competition for nutrients or binding site, and growth in intestinal mucus. A total of 50 bacterial strains were analyzed and only one showed excellent in vitro results for consideration as a candidate to be analyzed in vivo. The strain, identified as Vagococcus fluvialis, showed good protection against Vibrio anguillarum 975-1 in vivo in the experimental challenge, showing a relative percent survival of 42.3% higher than positive control group. Therefore, in conclusion we consider this strain to be a good candidate for use as a future probiotic in aquaculture.
Katrien Broekaert - One of the best experts on this subject based on the ideXlab platform.
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Spoilage potential of Vagococcus salmoninarum in preservative-free, MAP-stored brown shrimp and differentiation from Brochothrix thermosphacta on streptomycin thallous acetate actidione agar
Journal of applied microbiology, 2016Co-Authors: Fien Calliauw, Benjamin Horemans, Katrien Broekaert, Chris W. Michiels, Marc HeyndrickxAbstract:Aims During a previous study concerning brown shrimp (Crangon crangon), selective streptomycin thallous acetate actidione (STAA) agar was used to determine the growth of Brochothrix thermosphacta. However, the growth of Vagococcus salmoninarum on this medium was also noticed. This study explores the spoilage potential of this organism when inoculated on sterile shrimp. Methods and Results Isolates growing on STAA were identified using (GTG)5 clustering followed by partial 16S rRNA gene sequence analysis. Their biochemical spoilage potential was analysed for H2S production and enzymatic activities were tested using an APIZYM test. Headspace solid phase micro-extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to analyse the volatile organic compounds (VOCs) produced during storage of inoculated shrimp. Conclusion Fifty-five per cent of isolates taken from STAA could be identified as V. salmoninarum, while no apparent morphological difference with B. thermosphacta isolates was identified upon the prescribed incubation conditions. For isolates identified as V. salmoninarum, production of 2-heptanone, 2-nonanone, 2-undecanone was found, as was the possibility to form H2S. Significance and impact of the Study When using the STAA medium for detecting B. thermosphacta, one should consider the possible abundant presence of V. salmoninarum as well. Based on this study, V. salmoninarum does not exhibit great spoilage potential, although it can produce H2S and formed VOCs which are also found in other spoiled seafood products.
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assessment throughout a whole fishing year of the dominant microbiota of peeled brown shrimp crangon crangon stored for 7 days under modified atmosphere packaging at 4 c without preservatives
Food Microbiology, 2016Co-Authors: Fien Calliauw, Katrien Broekaert, Chris W. Michiels, Thijs De Mulder, Geertrui Vlaemynck, Marc HeyndrickxAbstract:Abstract This study was performed to comprehensively reveal the composition of the microbial community of commercially cooked and machine peeled brown shrimp ( Crangon crangon ), packaged and stored under modified atmosphere without added preservatives. Three independent experiments, using both culture-dependent and culture-independent methods, were conducted over an entire shrimp season. Initial total aerobic psychrotrophic bacterial counts (APC) were relatively high on several general media ranging between 5.4 and 6.4 log cfu g −1 . After 7 days of storage at 4 °C, samples were considered microbiologically spoiled with no apparent difference in APC between samples from different periods. The dominant microbiota present after 7 days of storage was assessed by (GTG) 5 analysis of selected colonies and 16S rRNA gene sequence analysis. The dominant organism on general media was Arthrobacter bergerei , whereas on more selective media Shewanella putrefaciens , Brochothrix thermosphacta and Vagococcus salmoninarum were most abundant. Culture-independent denaturant gradient gel electrophoresis (DGGE) and Illumina next generation sequencing revealed Carnobacterium as a dominant genus at day 7 throughout the year, together with members of Shewanella and Psychrobacter . The differences in relative abundance of dominant genera between different months also indicated a possible seasonal influence on the microbial community. It could be concluded that the same major groups of spoilage bacteria were retrieved by culture dependent and independent approaches, but their relative abundance differed.
