scholarly journals Comparison of the Effects of Environmental Parameters on Growth Rates of Vibrio vulnificus Biotypes I, II, and III by Culture and Quantitative PCR Analysis

2011 ◽  
Vol 77 (12) ◽  
pp. 4200-4207 ◽  
Author(s):  
Eva Chase ◽  
Valerie J. Harwood
Keyword(s):  
Quantitative Pcr ◽  
Growth Rates ◽  
Environmental Changes ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
Defined Medium ◽  
Pcr Analysis ◽  
Human Pathogens ◽  
Content Type ◽  
Specific Growth Rates

ABSTRACTVibrio vulnificusis a natural inhabitant of estuarine waters. The three known biotypes include (i) most human pathogens, (ii) primarily eel pathogens, and (iii) pathogens associated with fish and with human wound infections in Israel. Despite the frequently lethal consequences ofV. vulnificusinfections, the growth rates of the various biotypes and their response to environmental changes are not well characterized. We compared the specific growth rates (μ) of a representative of each biotype by culture and quantitative PCR (qPCR) analysis in a defined medium under varied pH, temperature, and salinity. Growth rates based on culturable concentrations were always higher than those based on qPCR estimates; however, both enumeration methods yielded comparable results on the influence of environmental factors on growth rates. Temperature (25°C, 30°C, 37°C), pH (7.0, 8.0), and salinity (5 to 40‰) all had significant effects on the μ of each biotype. Temperature had the greatest effect on the μ of biotype 1 (CMCP6), whereas salinity had the greatest effect on the μ of biotypes 2 (ATCC 33147) and 3 (302/99). The biotypes' growth rates varied significantly; biotype 1 grew most rapidly, while biotype 3 grew most slowly. The highest growth rates were achieved at 37°C, pH 7.0, and salinities of 15 to 30‰ (μ = 4.0, 2.9, and 2.4 generations h−1for biotypes 1, 2, and 3, respectively). Other strains of the biotypes yielded comparable results, suggesting that the physiological responses of the biotypes are differentially affected by parameters that are highly variable both in estuarine environments and between the free-living and pathogen states ofV. vulnificus.

scholarly journals Isolated Microbial Single Cells and Resulting Micropopulations Grow Faster in Controlled Environments

2012 ◽  
Vol 78 (19) ◽  
pp. 7132-7136 ◽  
Author(s):  
Christian Dusny ◽  
Frederik Sven Ole Fritzsch ◽  
Oliver Frick ◽  
Andreas Schmid
Keyword(s):  
Pichia Pastoris ◽  
Corynebacterium Glutamicum ◽  
Growth Rates ◽  
Specific Growth ◽  
Single Cells ◽  
Hansenula Polymorpha ◽  
Content Type ◽  
Controlled Environments ◽  
Specific Growth Rates ◽  
Extracellular Environment

ABSTRACTSingularized cells ofPichia pastoris,Hansenula polymorpha, andCorynebacterium glutamicumdisplayed specific growth rates under chemically and physically constant conditions that were consistently higher than those obtained in populations. This highlights the importance of single-cell analyses by uncoupling physiology and the extracellular environment, which is now possible using the Envirostat 2.0 concept.

scholarly journals Differences in Abundances of Total Vibrio spp., V. vulnificus, and V. parahaemolyticus in Clams and Oysters in North Carolina

2016 ◽  
Vol 83 (2) ◽  
Author(s):  
B. A. Froelich ◽  
B. Phippen ◽  
P. Fowler ◽  
R. T. Noble ◽  
J. D. Oliver
Keyword(s):  
North Carolina ◽  
Pathogenic Bacteria ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
Environmental Research ◽  
Overlying Water ◽  
Content Type ◽  
Source Of Infection ◽  
Bacterial Concentrations ◽  
Vibrio Spp

ABSTRACT Filter feeding shellfish can concentrate pathogenic bacteria, including Vibrio vulnificus and Vibrio parahaemolyticus, as much as 100-fold from the overlying water. These shellfish, especially clams and oysters, are often consumed raw, providing a route of entry for concentrated doses of pathogenic bacteria into the human body. The numbers of foodborne infections with these microbes are increasing, and a better understanding of the conditions that might trigger elevated concentrations of these bacteria in seafood is needed. In addition, if bacterial concentrations in water are correlated with those in shellfish, then sampling regimens could be simplified, as water samples can be more rapidly and easily obtained. After sampling of oysters and clams, either simultaneously or separately, for over 2 years, it was concluded that while Vibrio concentrations in oysters and water were related, this was not the case for levels in clams and water. When clams and oysters were collected simultaneously from the same site, the clams were found to have lower Vibrio levels than the oysters. Furthermore, the environmental parameters that were correlated with levels of Vibrio spp. in oysters and water were found to be quite different from those that were correlated with levels of Vibrio spp. in clams. IMPORTANCE This study shows that clams are a potential source of infection in North Carolina, especially for V. parahaemolyticus. These findings also highlight the need for clam-specific environmental research to develop accurate Vibrio abundance models and to broaden the ecological understanding of clam-Vibrio interactions. This is especially relevant as foodborne Vibrio infections from clams are being reported.

scholarly journals Development and Validation of a Predictive Model for the Growth of Vibrio vulnificus in Postharvest Shellstock Oysters

2012 ◽  
Vol 78 (6) ◽  
pp. 1675-1681 ◽  
Author(s):  
Ligia DaSilva ◽  
Salina Parveen ◽  
Angelo DePaola ◽  
John Bowers ◽  
Kathy Brohawn ◽  
...  
Keyword(s):  
Growth Rate ◽  
Chesapeake Bay ◽  
Predictive Model ◽  
Growth Rates ◽  
Vibrio Vulnificus ◽  
Assessment Model ◽  
Mobile Bay ◽  
Content Type ◽  
Wide Range ◽  
Eastern Oysters

ABSTRACTPostharvest growth ofVibrio vulnificusin oysters can increase risk of human infection. Unfortunately, limited information is available regardingV. vulnificusgrowth and survival patterns over a wide range of storage temperatures in oysters harvested from different estuaries and in different oyster species. In this study, we developed a predictive model forV. vulnificusgrowth in Eastern oysters (Crassostrea virginica) harvested from Chesapeake Bay, MD, over a temperature range of 5 to 30°C and then validated the model againstV. vulnificusgrowth rates (GRs) in Eastern and Asian oysters (Crassostrea ariakensis) harvested from Mobile Bay, AL, and Chesapeake Bay, VA, respectively. In the model development studies,V. vulnificuswas slowly inactivated at 5 and 10°C with average GRs of −0.0045 and −0.0043 log most probable number (MPN)/h, respectively. Estimated average growth rates at 15, 20, 25, and 30°C were 0.022, 0.042, 0.087, and 0.093 log MPN/h, respectively. With respect to Eastern oysters, bias (Bf) and accuracy (Af) factors for model-dependent and -independent data were 1.02 and 1.25 and 1.67 and 1.98, respectively. For Asian oysters,BfandAfwere 0.29 and 3.40. Residual variations in growth rate about the fitted model were not explained by season, region, water temperature, or salinity at harvest. Growth rate estimates for Chesapeake Bay and Mobile Bay oysters stored at 25 and 30°C showed relatively high variability and were lower than Food and Agricultural Organization (FAO)/WHOV. vulnificusquantitative risk assessment model predictions. The model provides an improved tool for designing and implementing food safety plans that minimize the risk associated withV. vulnificusin oysters.

scholarly journals Sediment and Vegetation as Reservoirs of Vibrio vulnificus in the Tampa Bay Estuary and Gulf of Mexico

2015 ◽  
Vol 81 (7) ◽  
pp. 2489-2494 ◽  
Author(s):  
Eva Chase ◽  
Suzanne Young ◽  
Valerie J. Harwood
Keyword(s):  
Gulf Of Mexico ◽  
Water Temperature ◽  
Quantitative Pcr ◽  
Significant Interaction ◽  
Aquatic Vegetation ◽  
Vibrio Vulnificus ◽  
Opportunistic Pathogen ◽  
Tampa Bay ◽  
Ambient Conditions ◽  
Content Type

ABSTRACTThe opportunistic pathogenVibrio vulnificusoccurs naturally in estuarine habitats and is readily cultured from water and oysters under warm conditions but infrequently at ambient conditions of <15°C. The presence ofV. vulnificusin other habitats, such as sediments and aquatic vegetation, has been explored much less frequently. This study investigated the ecology ofV. vulnificusin water by culture and quantitative PCR (qPCR) and in sediment, oysters, and aquatic vegetation by culture.V. vulnificussamples were taken from five sites around Tampa Bay, FL. Levels determined by qPCR and culture were significantly correlated (P= 0.0006;r= 0.352); however,V. vulnificuswas detected significantly more frequently by qPCR (85% of all samples) compared to culture (43%). CulturableV. vulnificusbacteria were recovered most frequently from oyster samples (70%), followed by vegetation and sediment (∼50%) and water (43%). Water temperature, which ranged from 18.5 to 33.4°C, was positively correlated withV. vulnificusconcentrations in all matrices but sediments. Salinity, which ranged from 1 to 35 ppt, was negatively correlated withV. vulnificuslevels in water and sediments but not in other matrices. Significant interaction effects between matrix and temperature support the hypothesis that temperature affectsV. vulnificusconcentrations differently in different matrices and that sediment habitats may serve as seasonal reservoirs forV. vulnificus.V. vulnificuslevels in vegetation have not been previously measured and reveal an additional habitat for this autochthonous estuarine bacterium.

scholarly journals Microbial Enterotypes, Inferred by the Prevotella-to-Bacteroides Ratio, Remained Stable during a 6-Month Randomized Controlled Diet Intervention with the New Nordic Diet

2013 ◽  
Vol 80 (3) ◽  
pp. 1142-1149 ◽  
Author(s):  
Henrik M. Roager ◽  
Tine R. Licht ◽  
Sanne K. Poulsen ◽  
Thomas M. Larsen ◽  
Martin I. Bahl
Keyword(s):  
Gut Microbiota ◽  
Quantitative Pcr ◽  
Dietary Intervention ◽  
Plasma Cholesterol ◽  
Biological Significance ◽  
Pcr Analysis ◽  
Dietary Interventions ◽  
Content Type ◽  
Nordic Diet ◽  
New Nordic Diet

ABSTRACTIt has been suggested that the human gut microbiota can be divided into enterotypes based on the abundance of specific bacterial groups; however, the biological significance and stability of these enterotypes remain unresolved. Here, we demonstrated that subjects (n= 62) 18 to 65 years old with central obesity and components of metabolic syndrome could be grouped into two discrete groups simply by their relative abundance ofPrevotellaspp. divided byBacteroidesspp. (P/Bratio) obtained by quantitative PCR analysis. Furthermore, we showed that these groups remained stable during a 6-month, controlled dietary intervention, where the effect of consuming a diet in accord with the new Nordic diet (NND) recommendations as opposed to consuming the average Danish diet (ADD) on the gut microbiota was investigated. In this study, subjects (with and without stratification according toP/Bratio) did not reveal significant changes in 35 selected bacterial taxa quantified by quantitative PCR (ADD compared to NND) resulting from the dietary interventions. However, we found higher total plasma cholesterol within the high-P/Bgroup than in the low-P/Bgroup after the intervention. We propose that stratification of humans based simply on theirP/Bratio could allow better assessment of possible effects of interventions on the gut microbiota and physiological biomarkers.

scholarly journals Pichia pastoris Exhibits High Viability and a Low Maintenance Energy Requirement at Near-Zero Specific Growth Rates

2016 ◽  
Vol 82 (15) ◽  
pp. 4570-4583 ◽  
Author(s):  
Corinna Rebnegger ◽  
Tim Vos ◽  
Alexandra B. Graf ◽  
Minoska Valli ◽  
Jack T. Pronk ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Growth Rates ◽  
Specific Growth ◽  
Energy Requirement ◽  
Maintenance Energy ◽  
Content Type ◽  
Chemostat Cultures ◽  
Zero Growth ◽  
Maintenance Energy Requirement ◽  
Specific Growth Rates

ABSTRACTThe yeastPichia pastorisis a widely used host for recombinant protein production. Understanding its physiology at extremely low growth rates is a first step in the direction of decoupling product formation from cellular growth and therefore of biotechnological relevance. Retentostat cultivation is an excellent tool for studying microbes at extremely low specific growth rates but has so far not been implemented forP. pastoris. Retentostat feeding regimes were based on the maintenance energy requirement (mS) and maximum biomass yield on glucose (YX/Smax) estimated from steady-state glucose-limited chemostat cultures. Aerobic retentostat cultivation enabled reproducible, smooth transitions from a specific growth rate (μ) of 0.025 h−1to near-zero specific growth rates (μ < 0.001 h−1). At these near-zero specific growth rates, viability remained at least 97%. The value ofmSat near-zero growth rates was 3.1 ± 0.1 mg glucose per g biomass and h, which was 3-fold lower than themSestimated from faster-growing chemostat cultures. This difference indicated thatP. pastorisreduces its maintenance energy requirement at extremely low μ, a phenomenon not previously observed in eukaryotes. Intracellular levels of glycogen and trehalose increased, while μ progressively declined during retentostat cultivation. Transcriptional reprogramming toward zero growth included the upregulation of many transcription factors as well as stress-related genes and the downregulation of cell cycle genes. This study underlines the relevance of comparative analysis of maintenance energy metabolism, which has an important impact on large-scale industrial processes.IMPORTANCEThe yeastPichia pastorisnaturally lives on trees and can utilize different carbon sources, among them glucose, glycerol, and methanol. In biotechnology, it is widely used for the production of recombinant proteins. For both the understanding of life in its natural habitat and optimized production processes, a better understanding of cell physiology at an extremely low growth rate would be of extraordinary value. Therefore, we have grownP. pastorisin a retentostat, which allows the cultivation of metabolically active cells even at zero growth. Here we reached doubling times as long as 38 days and found thatP. pastorisdecreases its maintenance energy demand 3-fold during very slow growth, which enables it to survive with a much lower substrate supply than baker's yeast.

scholarly journals Molecular Analysis of theIn SituGrowth Rates of Subsurface Geobacter Species

2012 ◽  
Vol 79 (5) ◽  
pp. 1646-1653 ◽  
Author(s):  
Dawn E. Holmes ◽  
Ludovic Giloteaux ◽  
Melissa Barlett ◽  
Milind A. Chavan ◽  
Jessica A. Smith ◽  
...  
Keyword(s):  
Growth Rates ◽  
Ribosomal Proteins ◽  
Specific Growth ◽  
Expression Patterns ◽  
Transcript Abundance ◽  
Metal Reduction ◽  
Content Type ◽  
Specific Growth Rates ◽  
Dissimilatory Metal Reduction

ABSTRACTMolecular tools that can provide an estimate of thein situgrowth rate ofGeobacterspecies could improve understanding of dissimilatory metal reduction in a diversity of environments. Whole-genome microarray analyses of a subsurface isolate ofGeobacter uraniireducens, grown under a variety of conditions, identified a number of genes that are differentially expressed at different specific growth rates. Expression of two genes encoding ribosomal proteins,rpsCandrplL, was further evaluated with quantitative reverse transcription-PCR (qRT-PCR) in cells with doubling times ranging from 6.56 h to 89.28 h. Transcript abundance ofrpsCcorrelated best (r2= 0.90) with specific growth rates. Therefore, expression patterns ofrpsCwere used to estimate specific growth rates ofGeobacterspecies during anin situuranium bioremediation field experiment in which acetate was added to the groundwater to promote dissimilatory metal reduction. Initially, increased availability of acetate in the groundwater resulted in higher expression ofGeobacter rpsC, and the increase in the number ofGeobactercells estimated with fluorescentin situhybridization compared well with specific growth rates estimated from levels ofin situ rpsCexpression. However, in later phases, cell number increases were substantially lower than predicted fromrpsCtranscript abundance. This change coincided with a bloom of protozoa and increased attachment ofGeobacterspecies to solid phases. These results suggest that monitoringrpsCexpression may better reflect the actual rate thatGeobacterspecies are metabolizing and growing duringin situuranium bioremediation than changes in cell abundance.

scholarly journals Development of a Matrix Tool for the Prediction of Vibrio Species in Oysters Harvested from North Carolina

2014 ◽  
Vol 81 (3) ◽  
pp. 1111-1119 ◽  
Author(s):  
B. A. Froelich ◽  
M. Ayrapetyan ◽  
P. Fowler ◽  
J. D. Oliver ◽  
R. T. Noble
Keyword(s):  
North Carolina ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
The United States ◽  
Human Infection ◽  
Management Tools ◽  
Specific Data ◽  
Content Type ◽  
Salinity Water

ABSTRACTThe United States has federal regulations in place to reduce the risk of seafood-related infection caused by the estuarine bacteriaVibrio vulnificusandVibrio parahaemolyticus. However, data to support the development of regulations have been generated in a very few specific regions of the nation. More regionally specific data are needed to further understand the dynamics of human infection relating to shellfish-harvesting conditions in other areas. In this study, oysters and water were collected from four oyster harvest sites in North Carolina over an 11-month period. Samples were analyzed for the abundances of totalVibriospp.,V. vulnificus, andV. parahaemolyticus; environmental parameters, including salinity, water temperature, wind velocity, and precipitation, were also measured simultaneously. By utilizing these data, preliminary predictive management tools for estimating the abundance ofV. vulnificusbacteria in shellfish were developed. This work highlights the need for further research to elucidate the full suite of factors that driveV. parahaemolyticusabundance.

scholarly journals Genomic and Metabolic Profiling of Nonulosonic Acids in Vibrionaceae Reveal Biochemical Phenotypes of Allelic Divergence in Vibrio vulnificus

2011 ◽  
Vol 77 (16) ◽  
pp. 5782-5793 ◽  
Author(s):  
Amanda L. Lewis ◽  
Jean-Bernard Lubin ◽  
Shilpa Argade ◽  
Natasha Naidu ◽  
Biswa Choudhury ◽  
...  
Keyword(s):  
Vibrio Vulnificus ◽  
Hot Spot ◽  
Gene Clusters ◽  
Human Pathogens ◽  
Environmental Isolates ◽  
Content Type ◽  
The Family ◽  
Domains Of Life ◽  
Biochemical Analyses ◽  
And Function

ABSTRACTNonulosonic acids (NulOs) encompass a large group of structurally diverse nine-carbon backbone α-keto sugars widely distributed among the three domains of life. Mammals express a specialized version of NulOs called sialic acids, which are displayed in prominent terminal positions of cell surface and secreted glycoconjugates. Within bacteria, the ability to synthesize NulOs has been demonstrated in a number of human pathogens and is phylogenetically widespread. Here we examine the distribution, diversity, evolution, and function of NulO biosynthesis pathways in members of the familyVibrionaceae. Among 27 species ofVibrionaceaeexamined at the genomic level, 12 species containednabgene clusters. We document examples of duplication, divergence, horizontal transfer, and recombination ofnabgene clusters in differentVibrionaceaelineages. Biochemical analyses, including mass spectrometry, confirmed that many species do, in fact, produce di-N-acetylated NulOs. A library of clinical and environmental isolates ofVibrio vulnificusserved as a model for further investigation ofnaballele genotypes and levels of NulO expression. The data show that lineage I isolates produce about 20-fold higher levels of NulOs than lineage II isolates. Moreover,nabgene alleles found in a subset ofV. vulnificusclinical isolates express 40-fold higher levels of NulOs thannaballeles associated with environmental isolates. Taken together, the data implicate the familyVibrionaceaeas a “hot spot” of NulO evolution and suggest that these molecules may have diverse roles in environmental persistence and/or animal virulence.

scholarly journals Ecology of Vibrio parahaemolyticus and Vibrio vulnificus in the Coastal and Estuarine Waters of Louisiana, Maryland, Mississippi, and Washington (United States)

2012 ◽  
Vol 78 (20) ◽  
pp. 7249-7257 ◽  
Author(s):  
Crystal N. Johnson ◽  
John C. Bowers ◽  
Kimberly J. Griffitt ◽  
Vanessa Molina ◽  
Rachel W. Clostio ◽  
...  
Keyword(s):  
United States ◽  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Vibrio Parahaemolyticus ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
The United States ◽  
Sea Surface ◽  
Content Type ◽  
Thermostable Direct Hemolysin

ABSTRACTVibrio parahaemolyticusandVibrio vulnificus, which are native to estuaries globally, are agents of seafood-borne or wound infections, both potentially fatal. Like all vibrios autochthonous to coastal regions, their abundance varies with changes in environmental parameters. Sea surface temperature (SST), sea surface height (SSH), and chlorophyll have been shown to be predictors of zooplankton and thus factors linked to vibrio populations. The contribution of salinity, conductivity, turbidity, and dissolved organic carbon to the incidence and distribution ofVibriospp. has also been reported. Here, a multicoastal, 21-month study was conducted to determine relationships between environmental parameters andV. parahaemolyticusandV. vulnificuspopulations in water, oysters, and sediment in three coastal areas of the United States. Because ecologically unique sites were included in the study, it was possible to analyze individual parameters over wide ranges. Molecular methods were used to detect genes for thermolabile hemolysin (tlh), thermostable direct hemolysin (tdh), andtdh-related hemolysin (trh) as indicators ofV. parahaemolyticusand the hemolysin genevvhAforV. vulnificus. SST and suspended particulate matter were found to be strong predictors of total and potentially pathogenicV. parahaemolyticusandV. vulnificus. Other predictors included chlorophylla, salinity, and dissolved organic carbon. For the ecologically unique sites included in the study, SST was confirmed as an effective predictor of annual variation in vibrio abundance, with other parameters explaining a portion of the variation not attributable to SST.

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