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Richards GP, Watson MA, Williams HN, Jones JL. Predator-Prey Interactions between Halobacteriovorax and Pathogenic Vibrio parahaemolyticus Strains: Geographical Considerations and Influence of Vibrio Hemolysins. Microbiol Spectr 2023; 11:e0235323. [PMID: 37409976 PMCID: PMC10434201 DOI: 10.1128/spectrum.02353-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 06/23/2023] [Indexed: 07/07/2023] Open
Abstract
Halobacteriovorax is a genus of naturally occurring marine predatory bacteria that attack, replicate within, and lyse vibrios and other bacteria. This study evaluated the specificity of four Halobacteriovorax strains against important sequence types (STs) of clinically relevant Vibrio parahaemolyticus, including pandemic strains ST3 and ST36. The Halobacteriovorax bacteria were previously isolated from seawater from the Mid-Atlantic, Gulf of Mexico, and Hawaiian coasts of the United States. Specificity screening was performed using a double agar plaque assay technique on 23 well-characterized and genomically sequenced V. parahaemolyticus strains isolated from infected individuals from widely varying geographic locations within the United States. With few exceptions, results showed that Halobacteriovorax bacteria were excellent predators of the V. parahaemolyticus strains regardless of the origins of the predator or prey. Sequence types and serotypes of V. parahaemolyticus did not influence host specificity, nor did the presence or absence of genes for the thermostable direct hemolysin (TDH) or the TDH-related hemolysin, although faint (cloudy) plaques were present when one or both hemolysins were absent in three of the Vibrio strains. Plaque sizes varied depending on both the Halobacteriovorax and Vibrio strains evaluated, suggesting differences in Halobacteriovorax replication and/or growth rates. The very broad infectivity of Halobacteriovorax toward pathogenic strains of V. parahaemolyticus makes Halobacteriovorax a strong candidate for use in commercial processing applications to enhance the safety of seafoods. IMPORTANCE Vibrio parahaemolyticus is a formidable obstacle to seafood safety. Strains pathogenic to humans are numerous and difficult to control, especially within molluscan shellfish. The pandemic spread of ST3 and ST36 has caused considerable concern, but many other STs are also problematic. The present study demonstrates broad predatory activity of Halobacteriovorax strains obtained along U.S. coastal waters from the Mid-Atlantic, Gulf Coast, and Hawaii toward strains of pathogenic V. parahaemolyticus. This broad activity against clinically relevant V. parahaemolyticus strains suggests a role for Halobacteriovorax in mediating pathogenic V. parahaemolyticus levels in seafoods and their environment as well as the potential application of these predators in the development of new disinfection technologies to reduce pathogenic vibrios in molluscan shellfish and other seafoods.
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Affiliation(s)
- Gary P. Richards
- U.S. Department of Agriculture, Agricultural Research Service, Delaware State University, Dover, Delaware, USA
| | - Michael A. Watson
- U.S. Department of Agriculture, Agricultural Research Service, Delaware State University, Dover, Delaware, USA
| | - Henry N. Williams
- School of the Environment, Florida Agricultural and Mechanical University, Tallahassee, Florida, USA
| | - Jessica L. Jones
- U.S. Food and Drug Administration, Division of Seafood Science and Technology, Gulf Coast Seafood Laboratory, Dauphin Island, Alabama, USA
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Kamada S, Wakabayashi R, Naganuma T. Phylogenetic Revisit to a Review on Predatory Bacteria. Microorganisms 2023; 11:1673. [PMID: 37512846 PMCID: PMC10385382 DOI: 10.3390/microorganisms11071673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Predatory bacteria, along with the biology of their predatory behavior, have attracted interest in terms of their ecological significance and industrial applications, a trend that has been even more pronounced since the comprehensive review in 2016. This mini-review does not cover research trends, such as the role of outer membrane vesicles in myxobacterial predation, but provides an overview of the classification and newly described taxa of predatory bacteria since 2016, particularly with regard to phylogenetic aspects. Among them, it is noteworthy that in 2020 there was a major phylogenetic reorganization that the taxa hosting Bdellovibrio and Myxococcus, formerly classified as Deltaproteobacteria, were proposed as the new phyla Bdellovibrionota and Myxococcota, respectively. Predatory bacteria have been reported from other phyla, especially from the candidate divisions. Predatory bacteria that prey on cyanobacteria and predatory cyanobacteria that prey on Chlorella have also been found. These are also covered in this mini-review, and trans-phylum phylogenetic trees are presented.
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Affiliation(s)
- Saki Kamada
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
| | - Ryoka Wakabayashi
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
| | - Takeshi Naganuma
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashihiroshima 739-8528, Japan
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Han Y, Xu X, Wang J, Cai H, Li D, Zhang H, Yang P, Meng K. Dietary Bacillus licheniformis shapes the foregut microbiota, improving nutrient digestibility and intestinal health in broiler chickens. Front Microbiol 2023; 14:1113072. [PMID: 36846755 PMCID: PMC9950405 DOI: 10.3389/fmicb.2023.1113072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/23/2023] [Indexed: 02/12/2023] Open
Abstract
Bacillus licheniformis is considered a potential alternative to antibiotic growth promoters of animal growth and health. However, the effects of Bacillus licheniformis on the foregut and hindgut microbiota, and their relationships with nutrient digestion and health, in broiler chickens remain unclear. In this study, we aimed to identify the effects of Bacillus licheniformis BCG on intestinal digestion and absorption, tight junctions, inflammation, and the fore- and hind-gut microbiota. We randomly assigned 240 1-day-old male AA broilers into three treatment groups: CT (basal diet), BCG1 (basal diet + 1.0 × 108 CFU/kg B. licheniformis BCG), and BCG2 (basal diet + 1.0 × 109 CFU/kg B. licheniformis BCG). On day 42, the jejunal and ileal chyme and mucosa were subjected to analysis of digestive enzyme activity, nutrient transporters, tight junctions, and signaling molecules associated with inflammation. The ileal and cecal chyme were subjected to microbiota analysis. Compared with the CT group, the B. licheniformis BCG group showed significantly greater jejunal and ileal α-amylase, maltase, and sucrase activity; moreover, the α-amylase activity in the BCG2 group was higher than that in the BCG1 group (P < 0.05). The transcript abundance of FABP-1 and FATP-1 in the BCG2 group was significantly greater than that in the CT and BCG1 groups, and the GLUT-2 and LAT-1 relative mRNA levels were greater in the BCG2 group than the CT group (P < 0.05). Dietary B. licheniformis BCG resulted in significantly higher ileal occludin, and lower IL-8 and TLR-4 mRNA levels than observed in the CT group (P < 0.05). B. licheniformis BCG supplementation significantly decreased bacterial community richness and diversity in the ileum (P < 0.05). Dietary B. licheniformis BCG shaped the ileac microbiota by increasing the prevalence of f_Sphingomonadaceae, Sphingomonas, and Limosilactobacillus, and contributed to nutrient digestion and absorption; moreover, it enhanced the intestinal barrier by increasing the prevalence of f_Lactobacillaceae, Lactobacillus, and Limosilactobacillus. Dietary B. licheniformis BCG decreased microbial community diversity by diminishing Desulfovibrio, Alistipes, Campylobacter, Vibrio, Streptococcus, and Escherichia coli-Shigella levels, and down-regulating inflammatory associated molecule expression. Therefore, dietary B. licheniformis BCG contributed to digestion and absorption of nutrients, enhanced the intestinal physical barrier, and decreased intestinal inflammation in broilers by decreasing microbial diversity and optimizing the microbiota structure.
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Affiliation(s)
- Yunsheng Han
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China
| | - Xin Xu
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China
| | - Jiaxin Wang
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China
| | - Hongying Cai
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China
| | - Daojie Li
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China
| | - Hongwei Zhang
- Chengde Academy of Agricultural and Forestry Sciences, Chengde, China
| | - Peilong Yang
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China,Peilong Yang,
| | - Kun Meng
- Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs, Institute of Feed Research, Chinese Academy of Agricultural Sciences (CAAS), Beijing, China,National Engineering Research Center of Biological Feed, Beijin, China,*Correspondence: Kun Meng,
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4
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Santos AA, Keim CN, Magalhães VF, Pacheco ABF. Microcystin drives the composition of small-sized bacterioplankton communities from a coastal lagoon. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:33411-33426. [PMID: 35029819 DOI: 10.1007/s11356-022-18613-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 01/07/2022] [Indexed: 06/14/2023]
Abstract
Cyanobacterial blooms affect biotic interactions in aquatic ecosystems, including those involving heterotrophic bacteria. Ultra-small microbial communities are found in both surface water and groundwater and include diverse heterotrophic bacteria. Although the taxonomic composition of these communities has been described in some environments, the involvement of these small cells in the fate of environmentally relevant molecules has not been investigated. Here, we aimed to test if small-sized microbial fractions from a polluted urban lagoon were able to degrade the cyanotoxin microcystin (MC). We obtained cells after filtration through 0.45 as well as 0.22 μm membranes and characterized the morphology and taxonomic composition of bacteria before and after incubation with and without microcystin-LR (MC-LR). Communities from different size fractions (< 0.22 and < 0.45 μm) were able to remove the dissolved MC-LR. The originally small-sized cells grew during incubation, as shown by transmission electron microscopy, and changed in both cell size and morphology. The analysis of 16S rDNA sequences revealed that communities originated from < 0.22 and < 0.45 μm fractions diverged in taxonomic composition although they shared certain bacterial taxa. The presence of MC-LR shifted the structure of < 0.45 μm communities in comparison to those maintained without toxin. Actinobacteria was initially dominant and after incubation with MC-LR Proteobacteria predominated. There was a clear enhancement of taxa already known to degrade MC-LR such as Methylophilaceae. Small-sized bacteria constitute a diverse and underestimated fraction of microbial communities, which participate in the dynamics of MC-LR in natural environments.
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Affiliation(s)
- Allan A Santos
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
| | - Carolina N Keim
- Laboratory of Geomicrobiology, Institute of Microbiology Paulo de Goés, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Valéria F Magalhães
- Laboratory of Ecophysiology and Toxicology of Cyanobacteria, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Ana Beatriz F Pacheco
- Laboratory of Biological Physics, Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Biocontrol Approaches against Escherichia coli O157:H7 in Foods. Foods 2022; 11:foods11050756. [PMID: 35267389 PMCID: PMC8909014 DOI: 10.3390/foods11050756] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/24/2022] [Accepted: 03/02/2022] [Indexed: 12/11/2022] Open
Abstract
Shiga-toxin-producing Escherichia coli O157:H7 is a well-known water- and food-borne zoonotic pathogen that can cause gastroenteritis in humans. It threatens the health of millions of people each year; several outbreaks of E. coli O157:H7 infections have been linked to the consumption of contaminated plant foods (e.g., lettuce, spinach, tomato, and fresh fruits) and beef-based products. To control E. coli O157:H7 in foods, several physical (e.g., irradiation, pasteurization, pulsed electric field, and high-pressure processing) and chemical (e.g., using peroxyacetic acid; chlorine dioxide; sodium hypochlorite; and organic acids, such as acetic, lactic, and citric) methods have been widely used. Although the methods are quite effective, they are not applicable to all foods and carry intrinsic disadvantages (alteration of sensory properties, toxicity, etc.). Therefore, the development of safe and effective alternative methods has gained increased attention recently. Biocontrol agents, including bacteriophages, probiotics, antagonistic bacteria, plant-derived natural compounds, bacteriocins, endolysins, and enzymes, are rapidly emerging as effective, selective, relatively safe for human consumption, and environmentally friendly alternatives. This paper summarizes advances in the application of biocontrol agents for E. coli O157:H7 control in foods.
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Williams HN, Chen H. Environmental Regulation of the Distribution and Ecology of Bdellovibrio and Like Organisms. Front Microbiol 2020; 11:545070. [PMID: 33193128 PMCID: PMC7658600 DOI: 10.3389/fmicb.2020.545070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/05/2020] [Indexed: 12/21/2022] Open
Abstract
The impact of key environmental factors, salinity, prey, and temperature, on the survival and ecology of Bdellovibrio and like bacteria (BALOs), including the freshwater/terrestrial, non-halotolerant group and the halophilic Halobacteriovorax strains, has been assessed based on a review of data in the literature. These topics have been studied by numerous investigators for nearly six decades now, and much valuable information has been amassed and reported. The collective data shows that salinity, prey, and temperature play a major role in, not only the growth and survival of BALOs, but also the structure and composition of BALO communities and the distribution of the predators. Salinity is a major determinant in the selection of BALO habitats, distribution, prey bacteria, and systematics. Halophilic BALOs require salt for cellular functions and are found only in saltwater habitats, and prey primarily on saltwater bacteria. To the contrary, freshwater/terrestrial BALOs are non-halotolerant and inhibited by salt concentrations greater than 0.5%, and are restricted to freshwater, soils, and other low salt environments. They prey preferentially on bacteria in the same habitats. The halophilic BALOs are further separated on the basis of their tolerance to various salt concentrations. Some strains are found in low salt environments and others in high salt regions. In situ studies have demonstrated that salinity gradients in estuarine systems govern the type of BALO communities that will persist within a specific gradient. Bacterial prey for BALOs functions more than just being a substrate for the predators and include the potential for different prey species to structure the BALO community at the phylotype level. The pattern of susceptibility or resistance of various bacteria species has been used almost universally to differentiate strains of new BALO isolates. However, the method suffers from a lack of uniformity among different laboratories. The use of molecular methods such as comparative analysis of the 16S rDNA gene and metagenomics have provided more specific approaches to distinguished between isolates. Differences in temperature growth range among different BALO groups and strains have been demonstrated in many laboratory experiments. The temperature optima and growth range for the saltwater BALOs is typically lower than that of the freshwater/terrestrial BALOs. The collective data shows not only that environmental factors have a great impact on BALO ecology, but also how the various factors affect BALO populations in nature.
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Affiliation(s)
- Henry N Williams
- School of the Environment, Florida Agricultural and Mechanical University, Tallahassee, FL, United States
| | - Huan Chen
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, United States
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Ottaviani D, Pieralisi S, Chierichetti S, Rocchegiani E, Hattab J, Mosca F, Tiscar PG, Leoni F, Angelico G. Vibrio parahaemolyticus control in mussels by a Halobacteriovorax isolated from the Adriatic sea, Italy. Food Microbiol 2020; 92:103600. [PMID: 32950141 DOI: 10.1016/j.fm.2020.103600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 07/03/2020] [Accepted: 07/21/2020] [Indexed: 02/08/2023]
Abstract
This study evaluated the application of a Halobacteriovorax isolated from water of the Adriatic Sea (Italy) in controlling V. parahaemolyticus in mussels (Mytilus galloprovincialis). Two 72 h laboratory-scale V. parahaemolyticus decontamination experiments of mussels were performed. The test microcosm of experiment 1 was prepared using predator/prey free mussels experimentally contaminated with Halobacteriovorax/V. parahaemolyticus at a ratio of 103 PFU/105 CFU per ml, while that of experiment 2 using mussels naturally harbouring Halobacteriovorax that were experimentally contaminated with 105 CFU per ml of V. parahaemolyticus. For experiment 1, was also tested a control microcosm only contaminated with 105 CFU per ml of V. parahaemolyticus.. Double layer agar plating and pour plate techniques were used to enumerate Halobacteriovorax and V. parahaemolyticus, respectively. 16 S rRNA analysis was used to identify Halobacteriovorax. For both experiments in the test microcosm the concentration of prey remained at the same level as that experimentally added, i.e. 5 log for the entire analysis period. In experiment 1, V. parahaemolyticus counts in mussels were significantly lower in the test microcosm than the control with the maximum difference of 2.2 log at 24 h. Results demonstrate that Halobacteriovorax can modulate V. parahaemolyticus level in the mussels. The public impact of V. parahaemolyticus in bivalves is relevant and current decontamination processes are not always effective. Halobacteriovorax is a suitable candidate in the development of a biological approach to the purification of V. parahaemolyticus in mussels.
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Affiliation(s)
- Donatella Ottaviani
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy.
| | - Silvia Pieralisi
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy
| | - Serena Chierichetti
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy
| | - Elena Rocchegiani
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy
| | - Jasmine Hattab
- Università degli Studi di Teramo, Facoltà di Medicina Veterinaria, Località Piano d'Accio, 64100, Teramo, Italy
| | - Francesco Mosca
- Università degli Studi di Teramo, Facoltà di Medicina Veterinaria, Località Piano d'Accio, 64100, Teramo, Italy
| | - Pietro Giorgio Tiscar
- Università degli Studi di Teramo, Facoltà di Medicina Veterinaria, Località Piano d'Accio, 64100, Teramo, Italy
| | - Francesca Leoni
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy
| | - Gabriele Angelico
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Controllo Alimenti, via Cupa di Posatora 3, 60126, Ancona, Italy
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Olanya O, Niemira B, Cassidy J, Boyd G, Uknalis J. Pathogen reduction by predatory bacteria and survival of Bdellovibrio bacteriovorus and Escherichia coli on produce and buffer treated with low-dose gamma radiation. Lebensm Wiss Technol 2020. [DOI: 10.1016/j.lwt.2020.109630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ottaviani D, Pieralisi S, Rocchegiani E, Latini M, Leoni F, Mosca F, Pallavicini A, Tiscar PG, Angelico G. Vibrio parahaemolyticus-specific Halobacteriovorax From Seawater of a Mussel Harvesting Area in the Adriatic Sea: Abundance, Diversity, Efficiency and Relationship With the Prey Natural Level. Front Microbiol 2020; 11:1575. [PMID: 32733427 PMCID: PMC7360731 DOI: 10.3389/fmicb.2020.01575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 06/17/2020] [Indexed: 11/13/2022] Open
Abstract
This research aimed to study the abundance and molecular diversity of Vibrio parahaemolyticus-specific Halobacteriovorax strains isolated from seawater of the Adriatic Sea and the relationship between predator and prey abundances. Moreover, predator efficiency of the Halobacteriovorax isolates toward V. parahaemolyticus and Vibrio cholerae non-O1/O139 strains was tested. V. parahaemolyticus NCTC 10885 was used as primary host for the isolation of Halobacteriovorax from seawater by the plaque assay. Molecular identification was performed by PCR detection of a fragment of the 16S rRNA gene of the Halobacteriovoraceae family members. Moreover, 700 bp PCR products were sequenced and compared between them and to clones described for other sampling sites. Vibrio counts were performed on TCBS agar from 100 ml of filtered water samples and presumptive colonies were confirmed by standard methods. Predatory efficiency of Halobacteriovorax isolates was tested by monitoring abilities of 3-day enrichments to form clear lytic halos on a lawn of Vibrio preys, by the plaque assay. Out of 12 seawater samples monthly collected from June 2017 to May 2018, 10 were positive for V. parahaemolyticus specific Halobacteriovorax with counts ranging from 4 to 1.4 × 103 PFU per 7.5 ml. No significant relationship was found between Halobacteriovorax and Vibrio abundances. The 16SrRNA sequences of our Halobacteriovorax strains, one for each positive sample, were divided into three lineages. Within the lineages, some sequences had 100% similarity. Sequence similarity between lineages was always <94.5% suggesting that they may therefore well belong to three different species. All Halobacteriovorax isolates had the ability to prey all tested Vibrio strains. Additional research is necessary to assess whether stable strains of Halobacteriovorax are present in the Adriatic Sea and to understand the mechanisms by which Halobacteriovorax may modulate the abundance of V. parahaemolyticus and other vibrios in a complex marine ecosystem.
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Affiliation(s)
- Donatella Ottaviani
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Silvia Pieralisi
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Elena Rocchegiani
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Mario Latini
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Francesca Leoni
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
| | - Francesco Mosca
- Facoltà di Medicina Veterinaria, Università degli Studi di Teramo, Teramo, Italy
| | - Alberto Pallavicini
- Facoltà di Biologia, Università degli Studi di Trieste, Trieste, Italy.,Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy
| | | | - Gabriele Angelico
- Laboratorio Controllo Alimenti, Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Ancona, Italy
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Buckley D, Annous BA, Vinyard B. Evaluation of chlorine dioxide gas release rates from dry precursors intended for applied technologies under disparate conditions and their effects on Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes. INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2020.102307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Tang BL, Yang J, Chen XL, Wang P, Zhao HL, Su HN, Li CY, Yu Y, Zhong S, Wang L, Lidbury I, Ding H, Wang M, McMinn A, Zhang XY, Chen Y, Zhang YZ. A predator-prey interaction between a marine Pseudoalteromonas sp. and Gram-positive bacteria. Nat Commun 2020; 11:285. [PMID: 31941905 PMCID: PMC6962226 DOI: 10.1038/s41467-019-14133-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/13/2019] [Indexed: 12/23/2022] Open
Abstract
Predator-prey interactions play important roles in the cycling of marine organic matter. Here we show that a Gram-negative bacterium isolated from marine sediments (Pseudoalteromonas sp. strain CF6-2) can kill Gram-positive bacteria of diverse peptidoglycan (PG) chemotypes by secreting the metalloprotease pseudoalterin. Secretion of the enzyme requires a Type II secretion system. Pseudoalterin binds to the glycan strands of Gram positive bacterial PG and degrades the PG peptide chains, leading to cell death. The released nutrients, including PG-derived D-amino acids, can then be utilized by strain CF6-2 for growth. Pseudoalterin synthesis is induced by PG degradation products such as glycine and glycine-rich oligopeptides. Genes encoding putative pseudoalterin-like proteins are found in many other marine bacteria. This study reveals a new microbial interaction in the ocean. Predator-prey interactions play important roles in the cycling of marine organic matter. Here the authors show that a Gram-negative bacterium isolated from marine sediments can kill and feed on Gram-positive bacteria by secreting a peptidoglycan-degrading enzyme.
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Affiliation(s)
- Bai-Lu Tang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Jie Yang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Peng Wang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China.,College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
| | - Hui-Lin Zhao
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Hai-Nan Su
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Chun-Yang Li
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China.,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China
| | - Yang Yu
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Shuai Zhong
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Lei Wang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Ian Lidbury
- School of Life Sciences, University of Warwick, Coventry, UK
| | - Haitao Ding
- SOA Key Laboratory for Polar Science, Polar Research Institute of China, Shanghai, 200136, China
| | - Min Wang
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China
| | - Andrew McMinn
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China.,Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Xi-Ying Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China
| | - Yin Chen
- College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China.,School of Life Sciences, University of Warwick, Coventry, UK
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, 266237, China. .,College of Marine Life Sciences, Institute for Advanced Ocean Study, Ocean University of China, Qingdao, 266003, China. .,Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266373, China.
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12
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Ottaviani D, Pieralisi S, Angelico G, Mosca F, Tiscar PG, Rocchegiani E, Scuota S, Petruzzelli A, Fisichella S, Blasi G, DiRaimo E, Leoni F, Latini M, Altissimi S, Haouet N. Bdellovibrio bacteriovorus
to control
Escherichia coli
on meat matrices. Int J Food Sci Technol 2019. [DOI: 10.1111/ijfs.14355] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Donatella Ottaviani
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Silvia Pieralisi
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Gabriele Angelico
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Francesco Mosca
- Facoltà di Medicina Veterinaria Università degli Studi di Teramo Località Piano d'Accio 64100 Teramo Italy
| | - Pietro Giorgio Tiscar
- Facoltà di Medicina Veterinaria Università degli Studi di Teramo Località Piano d'Accio 64100 Teramo Italy
| | - Elena Rocchegiani
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Stefania Scuota
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Annalisa Petruzzelli
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Stefano Fisichella
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Giuliana Blasi
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Enrico DiRaimo
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Francesca Leoni
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Mario Latini
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Serena Altissimi
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
| | - Naceur Haouet
- Laboratorio Controllo Alimenti Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche Via Cupa di Posatora 3 60126 Ancona Italy
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13
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Wang L, Zhan H, Wang Q, Wu G, Cui D. Enhanced aerobic granulation by inoculating dewatered activated sludge under short settling time in a sequencing batch reactor. BIORESOURCE TECHNOLOGY 2019; 286:121386. [PMID: 31078075 DOI: 10.1016/j.biortech.2019.121386] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/24/2019] [Accepted: 04/27/2019] [Indexed: 05/06/2023]
Abstract
The effect of dewatered activated sludge on aerobic granulation was investigated in a sequencing batch reactor (SBR) under short settling time. The results showed that dewatered sludge accelerated aerobic granulation and the granulation was completed within 5 days. On day 5, the aerobic granules were regular, compact, fast-settling and high granular strength and possessed excellent removal performance of carbon and nitrogen. The change trend of extracellular polymeric substances (EPS) was basically consistent with granular strength and granulation rate, indicating that EPS in granules played a vital function for granulation. Microbial community succession was investigated by pyrosequencing. In 5 days, microbial diversity was reduced and certain strains were rapidly enriched in the granules to become dominant species, serving on a crucial role in rapid granulation and pollutant removal as they could secrete excess EPS and possess the excellentability removing carbon and nitrogen pollutants.
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Affiliation(s)
- Lei Wang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, 221116 Xuzhou, China; School of Civil Engineering, Southwest Jiaotong University, 610031 Chengdu, China
| | - Hanhui Zhan
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, 221116 Xuzhou, China.
| | - Qingqing Wang
- School of Environment Science and Spatial Informatics, China University of Mining and Technology, 221116 Xuzhou, China
| | - Gang Wu
- School of Life Science and Engineering, Southwest Jiaotong University, 610031 Chengdu, China
| | - Dabin Cui
- School of Mechanical Engineering, Southwest Jiaotong University, 610031 Chengdu, China
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14
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Richards GP, Chintapenta LK, Watson MA, Abbott AG, Ozbay G, Uknalis J, Oyelade AA, Parveen S. Bacteriophages Against Pathogenic Vibrios in Delaware Bay Oysters (Crassostrea virginica) During a Period of High Levels of Pathogenic Vibrio parahaemolyticus. FOOD AND ENVIRONMENTAL VIROLOGY 2019; 11:101-112. [PMID: 30706411 DOI: 10.1007/s12560-019-09365-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Eastern oysters (Crassostrea virginica) from three locations along the Delaware Bay were surveyed monthly from May to October 2017 for levels of total Vibrio parahaemolyticus, pathogenic strains of V. parahaemolyticus and Vibrio vulnificus, and for strain-specific bacteriophages against vibrios (vibriophages). The objectives were to determine (a) whether vibriophages against known strains or serotypes of clinical and environmental vibrios were detectable in oysters from the Delaware Bay and (b) whether vibriophage presence or absence corresponded with Vibrio abundances in oysters. Host cells for phage assays included pathogenic V. parahaemolyticus serotypes O3:K6, O1:KUT (untypable) and O1:K1, as well as clinical and environmental strains of V. vulnificus. Vibriophages against some, but not all, pathogenic V. parahaemolyticus serotypes were readily detected in Delaware Bay oysters. In July, abundances of total and pathogenic V. parahaemolyticus at one site spiked to levels exceeding regulatory guidelines. Phages against three V. parahaemolyticus host serotypes were detected in these same oysters, but also in oysters with low V. parahaemolyticus levels. Serotype-specific vibriophage presence or absence did not correspond with abundances of total or pathogenic V. parahaemolyticus. Vibriophages were not detected against three V. vulnificus host strains, even though V. vulnificus were readily detectable in oyster tissues. Selected phage isolates against V. parahaemolyticus showed high host specificity. Transmission electron micrographs revealed that most isolates were ~ 60-nm diameter, non-tailed phages. In conclusion, vibriophages were detected against pandemic V. parahaemolyticus O3:K6 and O1:KUT, suggesting that phage monitoring in specific host cells may be a useful technique to assess public health risks from oyster consumption.
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Affiliation(s)
- Gary P Richards
- United States Department of Agriculture, Agricultural Research Service, Delaware State University, James Baker Center, Dover, DE, 19901, USA.
| | - Lathadevi K Chintapenta
- College of Agriculture Science and Technology, Delaware State University, Dover, DE, 19901, USA
- University of Wisconsin - River Falls, 410 S. 3rd Street, River Falls, WI, 54022, USA
| | - Michael A Watson
- United States Department of Agriculture, Agricultural Research Service, Delaware State University, James Baker Center, Dover, DE, 19901, USA
| | - Amanda G Abbott
- College of Agriculture Science and Technology, Delaware State University, Dover, DE, 19901, USA
| | - Gulnihal Ozbay
- College of Agriculture Science and Technology, Delaware State University, Dover, DE, 19901, USA
| | - Joseph Uknalis
- United States Department of Agriculture, Agricultural Research Service, Wyndmoor, PA, 19038, USA
| | - Abolade A Oyelade
- New Jersey Department of Environmental Protection, Leeds Point, NJ, USA
| | - Salina Parveen
- Department of Agriculture, Food and Resource Sciences, University of Maryland Eastern Shore, Princess Anne, MD, 21853, USA
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15
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Duan Y, Wang Y, Dong H, Ding X, Liu Q, Li H, Zhang J, Xiong D. Changes in the Intestine Microbial, Digestive, and Immune-Related Genes of Litopenaeus vannamei in Response to Dietary Probiotic Clostridium butyricum Supplementation. Front Microbiol 2018; 9:2191. [PMID: 30283419 PMCID: PMC6156435 DOI: 10.3389/fmicb.2018.02191] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 08/27/2018] [Indexed: 01/12/2023] Open
Abstract
The intestine barrier serves as the front-line defense in shrimp. Clostridium butyricum (CB) can produce butyric acid that provides energy for the intestine epithelial cells of the host. However, the effects of dietary CB on the intestine microbiome and the digestion and immunity of the host is not clear. In this study, we therefore investigated the composition and metabolic activity of the intestine microbiome, and digestive and immune-related gene expression in Litopenaeus vannamei fed with diets containing different levels of CB: basal diet (control), 2.5 × 109 CFU kg-1 diet (CB1), 5.0 × 109 CFU kg-1 diet (CB2), and 1.0 × 1010 CFU kg-1 diet (CB3) for 56 days. Dietary CB altered the composition of the intestine microbiome. Specifically, the dominant bacterial phylum Proteobacteria was enriched in the CB3 group and weakened in the CB1 and CB2 groups. The Bacteroidetes was enriched in the CB1 and CB2 groups and weakened in the CB3 group. The Firmicutes was enriched in all three CB groups. At the genus level, the potential pathogen (Desulfovibrio and Desulfobulbus) were weakened, and beneficial bacteria (Bacillus, Clostridium, Lachmoclostridium, Lachnospiraceae, and Lactobacillus) were enriched in response to dietary CB; these might contribute to the expression of the host digestive genes (α-amylase, lipase, trypsin, fatty acid-binding protein, and fatty acid synthase) and immune-related genes (prophenoloxidase, lipopolysaccharide and β-1,3-glucan binding protein, lysozyme, crustin, and superoxide dismutase). Additionally, CB enhanced the bacterial metabolism, especially that of carbohydrates, polymers, amino acids, carboxylic acids, and amines. These results revealed that dietary CB had a beneficial effect on the intestine health of L. vannamei by modulating the composition of the intestine microbiome, enhancing the microbial metabolism activity, and promoting the digestion and immunity of the host. The optimal dietary supplementation dosage was found to be 5.0 × 109 CFU kg-1 in the diet.
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Affiliation(s)
- Yafei Duan
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Yun Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Hongbiao Dong
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Xian Ding
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Qingsong Liu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Hua Li
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Jiasong Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
| | - Dalin Xiong
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, Key Laboratory of Fishery Ecology and Environment, Guangdong Province, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, China
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16
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Ottaviani D, Chierichetti S, Angelico G, Forte C, Rocchegiani E, Manuali E, Leoni F. Halobacteriovorax isolated from marine water of the Adriatic sea, Italy, as an effective predator of Vibrio parahaemolyticus, non-O1/O139 V. cholerae, V. vulnificus. J Appl Microbiol 2018; 125:1199-1207. [PMID: 29931749 DOI: 10.1111/jam.14027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 06/04/2018] [Accepted: 06/15/2018] [Indexed: 12/01/2022]
Abstract
AIM To detect marine Bdellovibrio and like organisms (BALOs) which are able to infect Vibrio parahaemolyticus from seawater of the Adriatic, Italy. To test, prey specificity and predation efficiency of our Halobacteriovorax isolate, named HBXCO1, towards 17 Vibrio and 7 non-Vibrio strains linked to the Adriatic sea, Italy. METHODS AND RESULTS Double layer agar plating technique was used to enumerate BALOs and to evaluate their prey specificity and predation efficiency. Transmission electron microscopy and 16S rRNA analysis were used to identify them. Means of BALOs counts ranged from 5·0 PFU per ml (March 2017) to 98·6 PFU per ml (August 2016). HBXCO1 had the ability to attack all tested prey strains of V. parahaemolyticus, Vibrio cholerae non-O1/O139 and Vibrio vulnificus, but it did not prey on non-Vibrio strains and V. alginolyticus under the tested conditions. CONCLUSIONS Bdellovibrio and like organisms capable of infecting pathogenic vibrios are naturally present in seawater of the Adriatic, Italy. Isolate HBXCO1 shows prey specificity preferentially for the Vibrio genus and high predatory efficiency towards a wide range of pathogenic strains. SIGNIFICANCE AND IMPACT OF THE STUDY The public impact of V. parahaemolyticus, non-O1/O139 V. cholerae and V. vulnificus in bivalves is relevant and current decontamination processes are not always effective. We believe that the predator HBXCO1 represents a potential candidate for the development of strategies of biocontrol of pathogenic vibrios in bivalves from harvesting to trade.
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Affiliation(s)
- D Ottaviani
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - S Chierichetti
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - G Angelico
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - C Forte
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - E Rocchegiani
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - E Manuali
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
| | - F Leoni
- Istituto Zooprofilattico Sperimentale dell'Umbria e delle Marche, Laboratorio Nazionale di Riferimento per il controllo delle Contaminazioni Batteriche dei Molluschi Bivalvi Vivi, Ancona, Italy
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17
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Relative Contributions of Halobacteriovorax and Bacteriophage to Bacterial Cell Death under Various Environmental Conditions. mBio 2018; 9:mBio.01202-18. [PMID: 30087166 PMCID: PMC6083911 DOI: 10.1128/mbio.01202-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The role of protists and bacteriophages in bacterial predation in the microbial food web has been well studied. There is mounting evidence that Bdellovibrio and like organisms (BALOs) also contribute to bacterial mortality and, in some cases, more so than bacteriophages. A full understanding of the ecologic function of the microbial food web requires recognition of all major predators and the magnitude of each predator’s contribution. Here we investigated the contribution of Halobacteriovorax, one of the BALOs, and bacteriophages when incubated with their common prey, Vibrio vulnificus, in a seawater microcosm. We observed that Halobacteriovorax was the greatest responder to the prey, increasing 18-fold with a simultaneous 4.4-log-unit reduction of V. vulnificus at 40 h, whereas the bacteriophage population showed no significant increase. In subsequent experiments to formulate a medium that would support the predatory activities and replication of both predators, low-nutrient media favored the predation and replication of the Halobacteriovorax, whereas higher-nutrient media enhanced phage growth. The greatest prey reduction and replication of both Halobacteriovorax and phage were observed in media with moderate nutrient levels. Additional experiments show that the predatory activities of both predators were influenced by environmental conditions, specifically, temperature and salinity. The two predators combined exerted greater control on V. vulnificus, a synergism that may be exploited for practical applications to reduce bacterial populations. These findings suggest that along with bacteriophage and protists, Halobacteriovorax has the potential to have a prominent role in bacterial mortality and cycling of nutrients, two vital ecologic functions. Although much has been reported about the marine microbial food web and the role of micropredators, specifically viruses and protists, the contribution of Bdellovibrio-like predators has largely been ignored, posing a major gap in understanding food web processes. A complete scenario of the microbial food web cannot be developed until the roles of all major micropredators and the magnitude of their contributions to bacterial mortality, structuring of microbial communities, and cycling of nutrients are assessed. Here we show compelling evidence that Halobacteriovorax, a predatory bacterium, is a significant contributor to bacterial death and, in some cases, may rival viruses as agents of bacterial mortality. These results advance current understanding of the microbial loop and top-down control on the bacterial community.
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18
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Liu J, Tian Z, Zhang P, Qiu G, Wu Y, Zhang H, Xu R, Fang W, Ye J, Song Y, Zeng G. Influence of reflux ratio on two-stage anoxic/oxic with MBR for leachate treatment: Performance and microbial community structure. BIORESOURCE TECHNOLOGY 2018; 256:69-76. [PMID: 29428616 DOI: 10.1016/j.biortech.2018.01.146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/27/2018] [Accepted: 01/31/2018] [Indexed: 06/08/2023]
Abstract
A lab-scale two-stage Anoxic/Oxic with MBR (AO/AO-MBR) system was operated for 81 days for leachate treatment with different reflux ratio (R). The best system performances were observed with a R value of 150%, and the average removal efficiencies of chemical oxygen demand, ammonia and total nitrogen were 85.6%, 99.1%, and 77.6%, respectively. The microbial community were monitored and evaluated using high-throughput sequencing. Proteobacteria were dominant in all process. Phylogenetic trees were described at species level, genus Thiopseudomonas, Amaricoccus, Nitrosomonas and Nitrobacter played significant roles in nitrogen removal. Co-occurrence analyzing top 20 genera showed that Nitrosomonas-Nitrobacter presented perfect positive relationship, as well as Paracoccus-Brevundimonas and Pusillimonas-Halobacteriovorax.
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Affiliation(s)
- Jianbo Liu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Zhiyong Tian
- Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Panyue Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China; School of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404632, China.
| | - Guanglei Qiu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585, Singapore
| | - Yan Wu
- School of Environmental and Chemical Engineering, Chongqing Three Gorges University, Chongqing 404632, China
| | - Haibo Zhang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Rui Xu
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Wei Fang
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Jie Ye
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
| | - Yonghui Song
- Department of Urban Water Environmental Research, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Guangming Zeng
- College of Environmental Science and Engineering, Hunan University, Changsha 410082, China
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19
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Prey Range and Genome Evolution of Halobacteriovorax marinus Predatory Bacteria from an Estuary. mSphere 2018; 3:mSphere00508-17. [PMID: 29359184 PMCID: PMC5760749 DOI: 10.1128/msphere.00508-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/05/2017] [Indexed: 02/04/2023] Open
Abstract
Predatory bacteria attack and digest other bacteria and therefore may play a role in shaping microbial communities. To investigate phenotypic and genotypic variation in saltwater-adapted predatory bacteria, we isolated Halobacteriovorax marinus BE01 from an estuary in Rhode Island, assayed whether it could attack different prey bacteria, and sequenced and analyzed its genome. We found that BE01 is a prey generalist, attacking bacteria from different phylogenetic groups and environments. Gene order and amino acid sequences are highly conserved between BE01 and the H. marinus type strain, SJ. By comparative genomics, we detected two regions of gene content difference that likely occurred via horizontal gene transfer events. Acquired genes encode functions such as modification of DNA, membrane synthesis and regulation of gene expression. Understanding genome evolution and variation in predation phenotypes among predatory bacteria will inform their development as biocontrol agents and clarify how they impact microbial communities. Halobacteriovorax strains are saltwater-adapted predatory bacteria that attack Gram-negative bacteria and may play an important role in shaping microbial communities. To understand how Halobacteriovorax strains impact ecosystems and develop them as biocontrol agents, it is important to characterize variation in predation phenotypes and investigate Halobacteriovorax genome evolution. We isolated Halobacteriovorax marinus BE01 from an estuary in Rhode Island using Vibrio from the same site as prey. Small, fast-moving, attack-phase BE01 cells attach to and invade prey cells, consistent with the intraperiplasmic predation strategy of the H. marinus type strain, SJ. BE01 is a prey generalist, forming plaques on Vibrio strains from the estuary, Pseudomonas from soil, and Escherichia coli. Genome analysis revealed extremely high conservation of gene order and amino acid sequences between BE01 and SJ, suggesting strong selective pressure to maintain the genome in this H. marinus lineage. Despite this, we identified two regions of gene content difference that likely resulted from horizontal gene transfer. Analysis of modal codon usage frequencies supports the hypothesis that these regions were acquired from bacteria with different codon usage biases than H. marinus. In one of these regions, BE01 and SJ carry different genes associated with mobile genetic elements. Acquired functions in BE01 include the dnd operon, which encodes a pathway for DNA modification, and a suite of genes involved in membrane synthesis and regulation of gene expression that was likely acquired from another Halobacteriovorax lineage. This analysis provides further evidence that horizontal gene transfer plays an important role in genome evolution in predatory bacteria. IMPORTANCE Predatory bacteria attack and digest other bacteria and therefore may play a role in shaping microbial communities. To investigate phenotypic and genotypic variation in saltwater-adapted predatory bacteria, we isolated Halobacteriovorax marinus BE01 from an estuary in Rhode Island, assayed whether it could attack different prey bacteria, and sequenced and analyzed its genome. We found that BE01 is a prey generalist, attacking bacteria from different phylogenetic groups and environments. Gene order and amino acid sequences are highly conserved between BE01 and the H. marinus type strain, SJ. By comparative genomics, we detected two regions of gene content difference that likely occurred via horizontal gene transfer events. Acquired genes encode functions such as modification of DNA, membrane synthesis and regulation of gene expression. Understanding genome evolution and variation in predation phenotypes among predatory bacteria will inform their development as biocontrol agents and clarify how they impact microbial communities.
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20
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McNeely D, Chanyi RM, Dooley JS, Moore JE, Koval SF. Biocontrol of Burkholderia cepacia complex bacteria and bacterial phytopathogens by Bdellovibrio bacteriovorus. Can J Microbiol 2016; 63:350-358. [PMID: 28177793 DOI: 10.1139/cjm-2016-0612] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Bdellovibrio and like organisms are predatory bacteria that have the unusual property of using the cytoplasmic constituents of other Gram-negative bacteria as nutrients. These predators may thus provide an alternative approach to the biocontrol of human and plant pathogens. Predators were isolated on Burkholderia cenocepacia K56-2 and J2315 as prey cells, in enrichment cultures with soil and sewage. Three isolates (DM7C, DM8A, and DM11A) were identified as Bdellovibrio bacteriovorus on the basis of morphology, a periplasmic life cycle, and 16S rRNA gene sequencing. The prey range of these isolates was tested on Burkholderia cepacia complex bacteria and several phytopathogenic bacteria of agricultural importance. Of 31 strains of the Burkholderia cepacia complex tested, only 4 were resistant to predation by strain DM7C. A subset of 9 of the prey tested were also susceptible to strains DM8A and DM11A. Of 12 phytopathogens tested, 4 were resistant to strains DM7C and DM8A, and only 2 were resistant to strain DM11A. Thus, Bdellovibrio bacteriovorus strains retrieved from environmental samples on 2 Burkholderia cenocepacia isolates from cystic fibrosis patients did not distinguish in their prey range between other isolates of that pathogen or phytopathogens. Such strains hold promise as potential wide-spectrum biocontrol agents.
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Affiliation(s)
- Damian McNeely
- a Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada.,b School of Biomedical Sciences, Faculty of Life and Health Sciences, Ulster University, Cromore Road, Coleraine, Co. Londonderry, BT52 1SA, Northern Ireland
| | - Ryan M Chanyi
- a Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada.,c Division of Urology, Department of Surgery, Lawson Health Research Institute, St. Joseph's Hospital, London, ON N6A 4V2, Canada
| | - James S Dooley
- b School of Biomedical Sciences, Faculty of Life and Health Sciences, Ulster University, Cromore Road, Coleraine, Co. Londonderry, BT52 1SA, Northern Ireland
| | - John E Moore
- b School of Biomedical Sciences, Faculty of Life and Health Sciences, Ulster University, Cromore Road, Coleraine, Co. Londonderry, BT52 1SA, Northern Ireland.,d Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast BT9 7AD, Northern Ireland
| | - Susan F Koval
- a Department of Microbiology and Immunology, University of Western Ontario, London, ON N6A 5C1, Canada
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