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McIlwraith HK, Lindeque PK, Miliou A, Tolhurst TJ, Cole M. Microplastic shape influences fate in vegetated wetlands. Environ Pollut 2024; 345:123492. [PMID: 38311156 DOI: 10.1016/j.envpol.2024.123492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 02/10/2024]
Abstract
Coastal areas are prone to plastic accumulation due to their proximity to land based sources. Coastal vegetated habitats (e.g., seagrasses, saltmarshes, mangroves) provide a myriad of ecosystem functions, such as erosion protection, habitat refuge, and carbon storage. The biological and physical factors that underlie these functions may provide an additional benefit: trapping of marine microplastics. While microplastics occurrence in coastal vegetated sediments is well documented, there is conflicting evidence on whether the presence of vegetation enhances microplastics trapping relative to bare sites and the factors that influence microplastic trapping remain understudied. We investigated how vegetation structure and microplastic type influences trapping in a simulated coastal wetland. Through a flume experiment, we measured the efficiency of microplastic trapping in the presence of branched and grassy vegetation and tested an array of microplastics that differ in shape, size, and polymer. We observed that the presence of vegetation did not affect the number of microplastics trapped but did affect location of deposition. Microplastic shape, rather than polymer, was the dominant factor in determining whether microplastics were retained in the sediment or adhered to the vegetation canopy. Across the canopy, microfibre concentrations decreased from the leading edge to the interior which suggests that even on a small-scale, vegetation has a filtering effect. The outcome of this study enriches our understanding of coastal vegetation as a microplastics sink and that differences among microplastics informs where they are most likely to accumulate within a biogenic canopy.
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Affiliation(s)
- Hayley K McIlwraith
- Marine Ecology & Biodiversity, Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK; University of East Anglia, School of Environmental Sciences, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Penelope K Lindeque
- Marine Ecology & Biodiversity, Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK
| | - Anastasia Miliou
- Archipelagos Institute of Marine Conservation, Pythagorio, Samos, 83103, Greece
| | - Trevor J Tolhurst
- University of East Anglia, School of Environmental Sciences, Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Matthew Cole
- Marine Ecology & Biodiversity, Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK.
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Cozzolino L, Nicastro KR, Seuront L, McQuaid CD, Zardi GI. The relative effects of interspecific and intraspecific diversity on microplastic trapping in coastal biogenic habitats. Sci Total Environ 2022; 848:157771. [PMID: 35926622 DOI: 10.1016/j.scitotenv.2022.157771] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/26/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Our understanding of how anthropogenic stressors such as climate change and plastic pollution interact with biodiversity is being widened to include diversity below the species level, i.e., intraspecific variation. The emerging appreciation of the key ecological importance of intraspecific diversity and its potential loss in the Anthropocene, further highlights the need to assess the relative importance of intraspecific versus interspecific diversity. One such issue is whether a species responds as a homogenous whole to plastic pollution. Using manipulative field transplant experiments and laboratory-controlled hydrodynamic simulations, we assessed the relative effects of intraspecific and interspecific diversity on microplastic trapping in coastal biogenic habitats dominated by two key bioengineers, the brown intertidal macroalgae Fucus vesiculosus and F. guiryi. At the individual level, northern morphotypes of F. guiryi trapped more microplastics than southern individuals, and F. vesiculosus trapped more microplastics than F. guiryi. Canopy density varied among species, however, leading to reversed patterns of microplastic accumulation, with F. guiryi canopies accumulating more microplastics than those of F. vesiculosus, while no differences were observed between the canopies of F. guiryi morphotypes. We emphasize the importance of assessing the effects of intraspecific variation which, along with other crucial factors such as canopy density, flow velocity and polymer composition, modulates the extent of microplastic accumulation in coastal biogenic habitats. Our findings indicate that a realistic estimation of plastic accumulation in biogenic habitats requires an understanding of within- and between-species traits at both the individual and population levels.
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Affiliation(s)
- Lorenzo Cozzolino
- CCMAR-Centro de Ciencias do Mar, CIMAR Laboratório Associado, Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal.
| | - Katy R Nicastro
- CCMAR-Centro de Ciencias do Mar, CIMAR Laboratório Associado, Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal; Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, F-59000 Lille, France; Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa
| | - Laurent Seuront
- Univ. Lille, CNRS, Univ. Littoral Côte d'Opale, UMR 8187 - LOG - Laboratoire d'Océanologie et de Géosciences, F-59000 Lille, France; Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa; Department of Marine Resources and Energy, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Christopher D McQuaid
- Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa
| | - Gerardo I Zardi
- Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa; Normandie Université, UNICAEN, Laboratoire Biologie des Organismes et Ecosystèmes Aquatiques, UMR 8067 BOREA (CNRS, MNHN, UPMC, UCBN, IRD-207), CS 14032, 14000 Caen, France
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Mendes-Oliveira G, Luo Y, Zhou B, Gu G, Teng Z, Bolten S, Park E, Pearlstein D, Turner ER, Millner PD, Nou X. Use of a silver-based sanitizer to accelerate Escherichia coli die-off on fresh-cut lettuce and maintain produce quality during cold storage: Laboratory and pilot-plant scale tests. Food Res Int 2022; 157:111170. [PMID: 35761517 DOI: 10.1016/j.foodres.2022.111170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 11/16/2022]
Abstract
Outbreaks and product recalls involving romaine and iceberg lettuce are frequently reported in the United States. Novel technologies are needed to inactivate pathogens without compromising product quality and shelf life. In this study, the effects of a process aid composed of silver dihydrogen citrate, glycerin, and lactic acid (SGL) on Escherichia coli and Listeria monocytogenes concentrations on lettuce immediately after washing and during cold storage were evaluated. Sensory and quality attributes of fresh-cut iceberg lettuce were also evaluated. Laboratory results indicated that application of SGL solution for 30 s as a first step in the washing process resulted in a 3.15 log reduction in E. coli O157:H7 immediately after washing. For E. coli O157:H7 a significant difference between SGL treatment and all other treatments was maintained until day 7. On day zero, SGL led to a 2.94 log reduction of L. monocytogenes. However, there was no significant difference between treatments with or without SGL regardless of storage time. Pilot-plant results showed that samples receiving SGL spray followed by chlorinated flume wash exhibited a greater reduction (1.48 log) in nonpathogenic E. coli populations at the end of shelf life than other treatments (p < 0.05). Additional pilot plant tests were conducted to investigate the hypothesis that SGL residues could continue to impact microbial survival on the final washed lettuce. Results show that pathogens introduced subsequent to flume washing of lettuce pretreated with SGL solution were not affected by antimicrobial residues. The final quality and shelf life of flume washed lettuce were also unaffected by pretreatment with SGL. In conclusion, the results of this study demonstrate that this new technology has the potential to accelerate E. coli die-off on fresh-cut lettuce during cold storage and improve product safety, while not affecting quality throughout the shelf life of the finished products.
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Affiliation(s)
- Gabriella Mendes-Oliveira
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Yaguang Luo
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States; Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Bin Zhou
- Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Ganyu Gu
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Zi Teng
- Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Samantha Bolten
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Eunhee Park
- Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Daniel Pearlstein
- Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Ellen R Turner
- Food Quality Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
| | - Patricia D Millner
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States.
| | - Xiangwu Nou
- Environmental Microbial and Food Safety Laboratory, United States Department of Agriculture, USDA-ARS, Beltsville, MD 20705, United States
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Ruiz-Navarro JJ, Andersen JT, Cuenca-Fernández F, López-Contreras G, Morouço PG, Arellano R. Quantification of swimmers' ability to apply force in the water: the potential role of two new variables during tethered swimming. Sports Biomech 2022:1-13. [PMID: 35714061 DOI: 10.1080/14763141.2022.2089220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 06/08/2022] [Indexed: 10/18/2022]
Abstract
This study aimed 1) to examine variables that may quantify the ability to apply force in the water and 2) to test their relationship with free swimming performance. Sixteen regional-level swimmers participated in this study. Average (Favg) and maximum (Fmax) forces were measured for 30 s arm stroke tethered swimming in a flume at zero and 1.389 m/s water flow speeds. The maximum and average force's relative changes (ΔFmax and ΔFavg, respectively) were calculated between tethered swimming at zero and 1.389 m/s water flow speeds. Free swimming speeds were obtained from 25, 50, and 100 m front crawl trials, and were correlated with ΔFmax and ΔFavg. A negative correlation was found between ΔFmax and 25, 50 and 100 m speeds (r = -0.84, r = -0.74, r = -0.55; p < 0.05, respectively) and ΔFavg correlated negatively with 25 and 50 m speeds (r = -0.63, r = -0.54; p < 0.05, respectively), but it did not correlate with 100 m swimming speed. The relative change in force could be used to quantify the ability to apply force in the water. This could aid coaches to understand if changes in swimmers' ability to apply force in the water contribute to improvements in performance.
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Affiliation(s)
- Jesús J Ruiz-Navarro
- Aquatics Lab, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Jordan T Andersen
- Sydney School of Health Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
- Biomechanics, Physical Performance, and Exercise (BioPPEx) Research Group, Macquarie University, NSW 2109, Australia
- Faculty of Medicine, Health and Human Sciences, Macquarie Universit, NSW 2109, Australia
| | - Francisco Cuenca-Fernández
- Aquatics Lab, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Gracia López-Contreras
- Aquatics Lab, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | - Pedro G Morouço
- ESECS, Polytechnic of Leiria, Portugal
- ciTechCare, Center for Innovative Care and Health Technology, Polytechnic of Leiria, Portugal
| | - Raúl Arellano
- Aquatics Lab, Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, Spain
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Bertoldi B, Bardsley CA, Pabst CR, Baker CA, Gutierrez A, De J, Luo Y, Schneider KR. Influence of Free Chlorine and Contact Time on the Reduction of Salmonella Cross-Contamination of Tomatoes in a Model Flume System. J Food Prot 2022; 85:22-26. [PMID: 34469547 DOI: 10.4315/jfp-21-212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/01/2021] [Indexed: 11/11/2022]
Abstract
ABSTRACT The process of washing tomatoes in dump (flume) tanks has been identified as a potential source of cross-contamination. This study's objective was to assess the potential for Salmonella enterica cross-contamination at various inoculation levels in the presence of free chlorine (HOCl) and organic matter. Uninoculated tomatoes were introduced into a laboratory-based model flume containing tomatoes inoculated with a cocktail of five rifampin-resistant S. enterica serovars at 104, 106, or 108 CFU per tomato in water containing 0 or 25 mg/L HOCl and 0 or 300 mg/L chemical oxygen demand (COD). Uninoculated tomatoes exposed to the inoculated tomatoes were removed from the water after 5, 30, 60, and 120 s and placed in bags containing tryptic soy broth supplemented with rifampin and 0.1% sodium thiosulfate. Following incubation, enrichment cultures were plated on tryptic soy agar supplemented with rifampin and xylose lysine deoxycholate agar to determine the presence of Salmonella. HOCl and pH were measured before and after each trial. The HOCl in water containing 300 mg/L COD significantly declined (P ≤ 0.05) by the end of each 120-s trial, most likely due to the increased demand for the oxidant. Higher inoculum levels and lower HOCl concentrations were significant factors (P ≤ 0.05) that contributed to increased cross-contamination. At 25 mg/L HOCl, no Salmonella was recovered under all conditions from uninoculated tomatoes exposed to tomatoes inoculated at 104 CFU per tomato. When the inoculum was increased to 106 and 108 CFU per tomato, cross-contamination was observed, independent of COD levels. The results from this study indicate that the currently required sanitizer concentration (e.g., 100 or 150 mg/L) for flume water may be higher than necessary and warrants reevaluation. HIGHLIGHTS
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Affiliation(s)
- Bruna Bertoldi
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Cameron A Bardsley
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher R Pabst
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Christopher A Baker
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Alan Gutierrez
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Jaysankar De
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
| | - Yaguang Luo
- U.S. Department of Agriculture, Agricultural Research Service, Environmental Microbial and Food Safety Laboratory, Beltsville, Maryland 20705, USA
| | - Keith R Schneider
- Department of Food Science and Human Nutrition, University of Florida, Gainesville, Florida 32611
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Lotufo GR, George RD, Belden JB, Woodley C, Smith DL, Rosen G. Release of Munitions Constituents in Aquatic Environments Under Realistic Scenarios and Validation of Polar Organic Chemical Integrative Samplers for Monitoring. Environ Toxicol Chem 2019; 38:2383-2391. [PMID: 31365142 DOI: 10.1002/etc.4553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/16/2019] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
Munitions constituents (MC) may be released into aquatic environments as a result of underwater military munitions (UWMM) corrosion and breach. The present study investigated the release of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) from Composition B fragments under 2 realistic exposure scenarios in a large flume with flow set at 15 cm/s: the first represented the release of MC from fully exposed Composition B, and the second represented release through a small hole, simulating a breached munition. Release of MC through a small hole was approximately 10 times lower than from exposed Composition B, demonstrating the strong influence of exposure to flow on release. The rate of release of MC into the flume was similar to that previously reported in a related field experiment, but a similar mass loss resulted in MC concentration in the field >300 times lower, likely by the dilution effect of hydrodynamic transport. The present study corroborates previous findings of release of MC at UWMM sites resulting in concentrations below the toxicity threshold to most species. In the flume water, MC was quantified using frequent grab sampling and polar organic chemical integrative samplers (POCIS). For TNT, POCIS-estimated time-weighted average concentrations were up to 40% higher than those derived from grab samples, whereas for RDX differences were 6% or less, demonstrating that POCIS provide reliable temporal integration of changing environmental concentrations for common MC. Environ Toxicol Chem 2019;38:2383-2391. Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
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Affiliation(s)
- Guilherme R Lotufo
- US Army Engineer Research and Development Center, Vicksburg, Mississippi
| | - Robert D George
- US Navy Space and Naval Warfare Systems Center Pacific, San Diego, California
| | - Jason B Belden
- Department of Zoology, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Christa Woodley
- US Army Engineer Research and Development Center, Vicksburg, Mississippi
| | - David L Smith
- US Army Engineer Research and Development Center, Vicksburg, Mississippi
| | - Gunther Rosen
- US Navy Space and Naval Warfare Systems Center Pacific, San Diego, California
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Lotufo GR, George RD, Belden JB, Woodley CM, Smith DL, Rosen G. Investigation of polar organic chemical integrative sampler (POCIS) flow rate dependence for munition constituents in underwater environments. Environ Monit Assess 2018; 190:171. [PMID: 29478103 DOI: 10.1007/s10661-018-6558-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
Munition constituents (MC) are present in aquatic environments throughout the world. Potential for fluctuating release with low residence times may cause concentrations of MC to vary widely over time at contaminated sites. Recently, polar organic chemical integrative samplers (POCIS) have been demonstrated to be valuable tools for the environmental exposure assessment of MC in water. Flow rate is known to influence sampling by POCIS. Because POCIS sampling rates (Rs) for MC have only been determined under quasi-static conditions, the present study evaluated the uptake of 2,4,6-trinitrotoluene (TNT), RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine), and 2,4- and 2,6-dinitrotoluenes (DNT), by POCIS in a controlled water flume at 7, 15, and 30 cm/s in 10-day experiments using samplers both within and without a protective cage. Sampling rate increased with flow rate for all MC investigated, but flow rate had the strongest impact on TNT and the weakest impact on RDX. For uncaged POCIS, mean Rs for 30 cm/s was significantly higher than that for 7 cm by 2.7, 1.9, 1.9, and 1.3 folds for TNT, 2,4-DNT, 2,6-DNT, and RDX, respectively. For all MC except RDX, mean Rs for caged POCIS at 7 cm/s were significantly lower than for uncaged samplers and similar to those measured at quasi-static condition, but except for 2,6-DNT, no caging effect was measured at the highest flow rate, indicating that the impact of caging on Rs is flow rate-dependent. When flow rates are known, flow rate-specific Rs should be used for generating POCIS-derived time-averaged concentrations of MC at contaminated sites.
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Affiliation(s)
- Guilherme R Lotufo
- U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS, 39180, USA.
| | - Robert D George
- U.S. Navy Space and Naval Warfare Systems Center Pacific, 53475 Strothe Rd., San Diego, CA, 92152, USA
| | - Jason B Belden
- Department of Zoology, Oklahoma State University, Stillwater, OK, 74078, USA
| | - Christa M Woodley
- U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS, 39180, USA
| | - David L Smith
- U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS, 39180, USA
| | - Gunther Rosen
- U.S. Navy Space and Naval Warfare Systems Center Pacific, 53475 Strothe Rd., San Diego, CA, 92152, USA
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Sreedharan A, Li Y, De J, Gutierrez A, Silverberg R, Schneider KR. Determination of Optimum Sanitizer Levels for Prevention of Salmonella Cross-Contamination of Mature Round Tomatoes in a Laboratory Model Flume System. J Food Prot 2017; 80:1436-1442. [PMID: 28782995 DOI: 10.4315/0362-028x.jfp-17-032] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella has been reported to be involved in several foodborne illness outbreaks, many of which resulted from consumption of raw tomatoes. This research aimed to optimize and evaluate the concentration of free chlorine (hypochlorous acid [HOCl]) used as a sanitizer to prevent cross-contamination of tomatoes inoculated with a cocktail of five rifampin-resistant Salmonella enterica serovars in a laboratory-based model flume system. Organic load, prepared using sterilized Scotts Premium Topsoil, was added in different quantities to the flume wash water to simulate real-world packinghouse conditions. In a typical packinghouse operation utilizing a recirculating flume system, the organic matter washed from tomato surfaces accumulates over time. In this study, different concentrations (0, 25, 50, 75, and 100 ppm) of HOCl were used as sanitizers under three organic load conditions (0, 650, and 1,000 mg/L chemical oxygen demand). Results showed that 100 ppm of HOCl was necessary to prevent Salmonella cross-contamination of uninoculated tomatoes in the model flume system in the presence of organic loading. Also, when treated with 100 ppm of HOCl, Salmonella levels were reduced by >4.5 log CFU per tomato from inoculated tomatoes in the presence of organic load. At 75 ppm of HOCl, Salmonella cross-contamination was prevented, but only in the absence of organic loading. In studies in which plate counts were negative, whole tomato enrichment studies were performed. No cross-contamination of uninoculated tomatoes was recorded when 100 ppm of HOCl was used, even in the presence of high organic load (1,000 mg/L chemical oxygen demand). Although sanitizer application reduces contamination on tomato surfaces, the primary function of sanitizers in the wash water is to prevent cross-contamination.
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Affiliation(s)
- Aswathy Sreedharan
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - You Li
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Jaysankar De
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Alan Gutierrez
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Rachael Silverberg
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
| | - Keith R Schneider
- Department of Food Science and Human Nutrition, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA
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Hockley FA, Wilson CAME, Graham N, Cable J. Combined effects of flow condition and parasitism on shoaling behaviour of female guppies Poecilia reticulata.. Behav Ecol Sociobiol 2014; 68:1513-1520. [PMID: 25152559 PMCID: PMC4133018 DOI: 10.1007/s00265-014-1760-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 11/03/2022]
Abstract
Group living in fish can provide benefits of protection from predators and some parasites, more efficient foraging for food, increased mating opportunities and enhanced energetic benefit when swimming. For riverine species, shoaling behaviour can be influenced by various environmental stressors, yet little is known how flow rate might influence the shoaling of diseased fish shoals. In view of the increasingly unpredictable flow rates in streams and rivers, this study aimed to assess the combined effect of flow condition and parasitism on the shoaling behaviour of a model fish species. Shoal size, shoal cohesion and time spent shoaling of female guppies Poecilia reticulata were compared when infected with the directly transmitted ectoparasite Gyrodactylus turnbulli under flow and static conditions. Flow condition was an important factor in influencing shoaling behaviour of guppies with the fish forming larger shoals in the absence of flow. When a shoal member was infected with G. turnbulli, shoal cohesion was reduced, but the magnitude of this effect was dependent on flow condition. In both flow and static conditions, bigger fish formed larger shoals than smaller counterparts. Future changes to stream hydrology with more frequent flooding and drought events will affect the shoaling tendency of fish. During high-flow events, diseased fish may not be able to keep up with shoal mates and therefore have a higher risk of predation. Additionally, these findings may be important for aquaria and farmed species where an increase in flow rate may reduce aggregation in fish.
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Affiliation(s)
- F A Hockley
- School of Biosciences, Cardiff University, Cardiff, UK
| | - C A M E Wilson
- Hydro-environmental Research Centre, School of Engineering, Cardiff University, Cardiff, UK
| | - N Graham
- School of Biosciences, Cardiff University, Cardiff, UK
| | - J Cable
- School of Biosciences, Cardiff University, Cardiff, UK
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