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FEMS Microbiology Ecology Feb 2024The skin of fish contains a diverse microbiota that has symbiotic functions with the host, facilitating pathogen exclusion, immune system priming, and nutrient...
The skin of fish contains a diverse microbiota that has symbiotic functions with the host, facilitating pathogen exclusion, immune system priming, and nutrient degradation. The composition of fish skin microbiomes varies across species and in response to a variety of stressors, however, there has been no systematic analysis across these studies to evaluate how these factors shape fish skin microbiomes. Here, we examined 1922 fish skin microbiomes from 36 studies that included 98 species and nine rearing conditions to investigate associations between fish skin microbiome, fish species, and water physiochemical factors. Proteobacteria, particularly the class Gammaproteobacteria, were present in all marine and freshwater fish skin microbiomes. Acinetobacter, Aeromonas, Ralstonia, Sphingomonas and Flavobacterium were the most abundant genera within freshwater fish skin microbiomes, and Alteromonas, Photobacterium, Pseudoalteromonas, Psychrobacter and Vibrio were the most abundant in saltwater fish. Our results show that different culturing (rearing) environments have a small but significant effect on the skin bacterial community compositions. Water temperature, pH, dissolved oxygen concentration, and salinity significantly correlated with differences in beta-diversity but not necessarily alpha-diversity. To improve study comparability on fish skin microbiomes, we provide recommendations for approaches to the analyses of sequencing data and improve study reproducibility.
Topics: Animals; Water; Phylogeny; Reproducibility of Results; Skin; Microbiota
PubMed: 38366921
DOI: 10.1093/femsec/fiae021 -
Marine Environmental Research Apr 2024The New Zealand Greenshell™ mussel (Perna canaliculus) is an economically important aquaculture species. Prolonged increases in seawater temperature above mussel...
Interactive effects of elevated temperature and Photobacterium swingsii infection on the survival and immune response of marine mussels (Perna canaliculus): A summer mortality scenario.
The New Zealand Greenshell™ mussel (Perna canaliculus) is an economically important aquaculture species. Prolonged increases in seawater temperature above mussel thermotolerance ranges pose a significant threat to mussel survival and health, potentially increasing susceptibility to bacterial infections. Using challenge experiments, this study examined the combined effects of increased seawater temperature and bacterial (Photobacterium swingsii) infection on animal survival, haemocyte and biochemical responses of adult mussels. Mussels maintained at three temperatures (16, 20 and 24 °C) for seven days were either not injected (control), injected with sterile marine broth (injection control) or P. swingsii (challenged with medium and high doses) and monitored daily for five days. Haemolymph and tissue samples were collected at 24, 48, 72, 96, 120 h post-challenge and analysed to quantify bacterial colonies, haemocyte responses and biochemical responses. Mussels infected with P. swingsii exhibited mortalities at 20 and 24 °C, likely due to a compromised immune system, but no mortalities were observed when temperature was the only stressor. Bacterial colony counts in haemolymph decreased over time, suggesting bacterial clearance followed by the activation of immune signalling pathways. Total haemocyte counts and viability data supports haemocyte defence functions being stimulated in the presence of high pathogen loads at 24 °C. In the gill tissue, oxidative stress responses, measured as total antioxidant capacity and malondialdehyde (MDA) levels, were higher in infected mussels (compared to the controls) after 24h and 120h post-challenge at the lowest (16 °C) and highest temperatures (24 °C), indicating the presence of oxidative stress due to temperature and pathogen stressors. Overall, this work confirms that Photobacterium swingsii is pathogenic to P. canaliculus and indicates that mussels may be more vulnerable to bacterial pathogens under conditions of elevated temperature, such as those predicted under future climate change scenarios.
Topics: Animals; Temperature; Perna; Photobacterium; Immunity
PubMed: 38364448
DOI: 10.1016/j.marenvres.2024.106392 -
Fish & Shellfish Immunology Mar 2024Immunonutrition is a promising and viable strategy for the development of prophylactic measures in aquaculture. Ulvan, a sulphated marine polysaccharide from green...
Immunonutrition is a promising and viable strategy for the development of prophylactic measures in aquaculture. Ulvan, a sulphated marine polysaccharide from green seaweeds, has many biological activities including the immunomodulatory ones. The aim of this study was to assess the short and long-term effects of an ulvan-rich extract obtained from U. ohnoi as immunonutrient in Senegalese sole juveniles. In this work, an ulvan-rich extract from Ulva ohnoi has been obtained by the hot water method and isolated by ethanol precipitation. The FTIR analysis revealed that the ulvan-rich extact had very similar characteristics to previously published ulvan spectra. The total sulfate and protein content was 24.85 ± 3.98 and 0.91 ± 0.04 %, respectively. In vitro assays performed in Senegalese sole (Solea senegalensis) macrophages showed that the ulvan obtained in this study did not compromise the cell viability at concentrations up to 1 mg ml and expression levels of lyg, irf1, il6, il10, c7, tf and txn were significantly upregulated in a concentration dependent-manner. Finally, S. senegalensis juveniles were fed basal diets and diets supplemented with the ulvan-rich extract at ratios 1 and 2 % for 30 days and then, challenged with Photobacterium damselae subsp. piscicida (Phdp). Thereafter, ulvan was withdrawn from the diet and all juveniles were fed the basal diet for 30 days. At 30 days post withdrawal (dpw), juveniles were challenged with Phdp. The expression profiles of a set of genes related to the immune system in spleen were evaluated as well as the lysozyme, peroxidase and bactericidal activity in plasma. Dietary effects of 1 % ulvan resulted in a boost of the immune response and increased disease resistance at short-term whereas juveniles fed diets supplemented with 2 % ulvan showed a significant decrease in the bactericidal activity and lack of protection against Phdp. At long-term (30 days after the withdrawal of ulvan), an improved response was observed in juveniles previously fed 1 % ulvan.
Topics: Animals; Fish Diseases; Gram-Negative Bacterial Infections; Polysaccharides; Flatfishes; Photobacterium
PubMed: 38296005
DOI: 10.1016/j.fsi.2024.109399 -
Foods (Basel, Switzerland) Jan 2024The bioactive properties of the combination of microencapsulated cell-free supernatant (CFS) from and thyme extract on food-related bacteria (, ATCC29213, ATCC29212,...
The bioactive properties of the combination of microencapsulated cell-free supernatant (CFS) from and thyme extract on food-related bacteria (, ATCC29213, ATCC29212, and Paratyphi A NCTC13) were investigated. The microencapsulated CFS of in combination with ethanolic thyme extract, had a particle size in the range of 1.11 to 11.39 µm. The microencapsulated CFS of had a wrinkled, spherical form. In the supernatant, especially at 2% (), the thyme extract additive caused a decrease in the wrinkled form and a completely spherical structure. A total of 11 compounds were determined in the cell-free supernatant of , and acetic acid (39.64%) and methyl-d3 1-dideuterio-2-propenyl ether (10.87%) were the main components. Thyme extract contained seven components, the main component being carvacrol at 67.96% and 1,2,3-propanetriol at 25.77%. Significant differences ( < 0.05) were observed in the inhibition zones of the extracts on bacteria. The inhibitory effect of thyme extract on bacteria varied between 25.00 () and 41.67 mm (). Less antibacterial activity was shown by the microencapsulated CFS from compared to their pure form. ( < 0.05). As a result, it was found that microencapsulated forms of CFS from especially those prepared in combination with 2% (/) thyme extract, generally showed higher bioactive effects on bacteria.
PubMed: 38275696
DOI: 10.3390/foods13020329 -
Immunity, Inflammation and Disease Jan 2024This study was designed to analyze the structural characteristics of the intestinal flora of elderly Uygur patients with sarcopenia, thereby providing new ideas for...
OBJECTIVE
This study was designed to analyze the structural characteristics of the intestinal flora of elderly Uygur patients with sarcopenia, thereby providing new ideas for clinical treatment.
METHODS
Firstly, fecal samples were collected from 40 elderly Uygur patients with sarcopenia (Sarcopenia group) and 40 healthy people (Control group). Next, significant differences in the intestinal flora between the two groups were analyzed based on 16S rDNA high-throughput sequencing. The linear discriminant analysis effect size (LEfSe) was used to estimate the magnitude of the effect of each component (species) abundance on the differential effect. Additionally, an analysis was also performed on the relationship between the intestinal flora and the cytokines in the peripheral blood of patients with sarcopenia.
RESULTS
The results of β diversity showed that there were differences in the structure of the intestinal flora between the two groups. Besides, the phylum level of intestinal flora between the two groups was not significantly different. However, the difference was significant in the intestinal flora at the order, family, and genus levels between the two groups. Among them, Lachnoclostridium, Photobacterium, Anaerobic Bacillus, Hydrogenophilus, and Eubacterium were enriched in the Sarcopenia group; Prevotella 9, Firmicutes FCS020 group, Streptobacillus, Aggregatibacter, Corynebacterium, Clostridium Difficile, and Haloanaerobium were enriched in the Control group. The LEfSe outcomes further showed that Lachnoclostridium was highly enriched in the Sarcopenia group; Prevotella 9 and Firmicutes FCS020 group were significantly enriched in the Control group. Furthermore, the relative abundance of Lachnoclostridium and Streptobacillus were significantly different in patients with high and low IL-6 levels.
CONCLUSION
In conclusion, Lachnoclostridium is significantly enriched in the intestines of elderly Uygur patients with sarcopenia; the increase in Lachnoclostridium abundance and the decrease in Streptobacillus abundance are associated with high levels of IL-6. Therefore, abnormal intestinal flora is related to inflammatory reflexes in patients with sarcopenia.
Topics: Aged; Humans; Gastrointestinal Microbiome; Interleukin-6; Sarcopenia; Cytokines; Feces
PubMed: 38270306
DOI: 10.1002/iid3.1097 -
Environmental Science and Pollution... Feb 2024Regulation of antibiotic use in aquaculture calls for the emergence of more sustainable alternative treatments. Tea polyphenols (GTE), particularly epigallocatechin...
Antimicrobial and antioxidant activity of encapsulated tea polyphenols in chitosan/alginate-coated zein nanoparticles: a possible supplement against fish pathogens in aquaculture.
Regulation of antibiotic use in aquaculture calls for the emergence of more sustainable alternative treatments. Tea polyphenols (GTE), particularly epigallocatechin gallate (EGCG), have various biological activities. However, tea polyphenols are susceptible to degradation. In this work, EGCG and GTE were encapsulated in zein nanoparticles (ZNP) stabilized with alginate (ALG) and chitosan (CS) to reduce the degradation effect. ALG-coated ZNP and ALG/CS-coated ZNP encapsulating EGCG or GTE were obtained with a hydrodynamic size of less than 300 nm, an absolute ζ-potential value >30 mV, and an encapsulation efficiency greater than 75%. The antioxidant capacity of the encapsulated substances, although lower than that of the free ones, maintained high levels. On the other hand, the evaluation of antimicrobial activity showed greater efficiency in terms of growth inhibition for ALG/CS-ZNP formulations, with average overall values of around 60%, reaching an inhibition of more than 90% for Photobacterium damselae. These results support encapsulation as a good strategy for tea polyphenols, as it allows maintaining significant levels of antioxidant activity and increasing the potential for antimicrobial activity, in addition to increasing protection against sources of degradation.
Topics: Animals; Antioxidants; Chitosan; Zein; Alginates; Polyphenols; Nanoparticles; Anti-Bacterial Agents; Tea; Organometallic Compounds; Pyridines
PubMed: 38261222
DOI: 10.1007/s11356-024-32058-x -
Journal of Zoo and Wildlife Medicine :... Jan 2024Septicemia is commonly suspected of sea turtles entering rehabilitation. However, blood culture results of green sea turtles () are infrequently reported in the...
RETROSPECTIVE ANALYSIS OF BLOOD CULTURES AND THEIR ASSOCIATION WITH CLINICAL FINDINGS AND OUTCOME IN GREEN SEA TURTLES () AT A FLORIDA SEA TURTLE REHABILITATION FACILITY, 2017-2020.
Septicemia is commonly suspected of sea turtles entering rehabilitation. However, blood culture results of green sea turtles () are infrequently reported in the literature. Aerobic blood cultures were performed for intake examinations of 167 green sea turtles undergoing rehabilitation at Brevard Zoo's Sea Turtle Healing Center, Melbourne, Florida, USA from 2017 to 2020. The incidence of positive cultures during intake examinations was 24% (40/167). The most common bacterial isolates identified were , , , , , and . There was a statistically significant association ( < 0.05) between culture status and evidence of external injury. There was no significant association between culture status and like coccidia infection, or fibropapillomatosis. Culture-positive turtles had significantly lower ( < 0.05) total white blood cell, lymphocyte, monocyte, total protein, albumin, and calculated globulin values compared to turtles with negative blood cultures. Significantly more culture-positive turtles died in rehabilitation compared to culture-negative ( = 0.042). Positive blood cultures suggestive of septicemia are commonly found during intake examinations at a Florida sea turtle rehabilitation facility.
Topics: Animals; Turtles; Blood Culture; Florida; Retrospective Studies; Sepsis
PubMed: 38252000
DOI: 10.1638/2022-0163 -
Journal of Invertebrate Pathology Mar 2024Greenshell™ mussels (Perna canaliculus) are endemic to New Zealand and support the largest aquaculture industry in the country. Photobacterium swingsii was isolated...
Greenshell™ mussels (Perna canaliculus) are endemic to New Zealand and support the largest aquaculture industry in the country. Photobacterium swingsii was isolated and identified from moribund P. canaliculus mussels following a mass mortality event. In this study, a challenge experiment was used to characterise, detect, and quantify P. swingsii in adult P. canaliculus following pathogen exposure via injection into the adductor muscle. A positive control (heat-killed P. swingsii injection) was included to account for the effects of injection and inactive bacterial exposure. Survival of control and infected mussels remained 100% during 72-hour monitoring period. Haemolymph was sampled for bacterial colony counts and haemocyte flow cytometry analyses; histology sections were obtained and processed for histopathological assessments; and adductor muscle, gill, digestive gland were sampled for quantitative polymerase chain reaction (PCR) analyses, all conducted at 12, 24, 48 h post-challenge (hpc). The most profound effects of bacterial injection on mussels were seen at 48 hpc, where mussel mortality, haemocyte counts and haemolymph bacterial colony forming were the highest. The quantification of P. swingsii via qPCR showed highest levels of bacterial DNA at 12 hpc in the adductor muscle, gill, and digestive gland. Histopathological observations suggested a non-specific inflammatory response in all mussels associated with a general stress response. This study highlights the physiological effects of P. swingsii infection in P. canaliculus mussels and provides histopathological insight into the tissue injury caused by the action of injection into the adductor muscle. The multi-technique methods used in this study can be applied for use in early surveillance programs of bacterial infection on mussel farms.
Topics: Animals; Perna; New Zealand; Photobacterium; Disease Progression
PubMed: 38246322
DOI: 10.1016/j.jip.2024.108065 -
Food Microbiology May 2024We aimed to evaluate the bacterial growth and diversity in vacuum-packed beef bags stored at different temperatures and to monitor blown-pack spoilage. We used...
We aimed to evaluate the bacterial growth and diversity in vacuum-packed beef bags stored at different temperatures and to monitor blown-pack spoilage. We used culture-based methods and high-throughput sequencing to study the development of the main bacterial groups naturally present in beef stored at 4 and 15 °C for 28 days. The growth of sulfite-reducing clostridium (SRC) was impaired in beef bags stored at 4 °C; significant differences among SRC counts were observed in beef bags stored at 4 and 15 °C on days 14, 21, and 28 (P = 0.001). Blown pack was observed in most beef bags stored at 15 °C, from day 14 to day 28, but not in beef bags stored at 4 °C. A storage temperature of 4 °C was able to maintain a stable bacterial microbiota (most prevalent: Photobacterium, Hafnia-Obesumbacterium, and Lactococcus). Remarkable changes in microbial abundance occurred at 15 °C from day 14 to day 28, with a predominance of strict anaerobes (Bacteroides) and the presence of Clostridium spp. The relative frequencies of strict anaerobes and Clostridium were statistically higher in the beef bags stored at 15 °C (P < 0.001 and P = 0.004, respectively). The temperature influenced the microbial counts and relative abundance of spoilage bacteria, leading to blown pack spoilage.
Topics: Animals; Cattle; Food Packaging; Meat; Temperature; Vacuum; Bacteria; Clostridium; Microbiota; Food Microbiology
PubMed: 38225050
DOI: 10.1016/j.fm.2023.104448 -
Fish & Shellfish Immunology Mar 2024A 56-d feeding trial was conducted to evaluate the influences of Rhodiola rosea L. on digestive enzyme activities, intestinal barrier, inflammatory response, and...
Rhodiola rosea L. improved intestinal digestive enzyme activities, inflammatory response, barrier and microbiota dysbiosis in Lateolabrax maculatus juveniles fed with high-carbohydrate diets.
A 56-d feeding trial was conducted to evaluate the influences of Rhodiola rosea L. on digestive enzyme activities, intestinal barrier, inflammatory response, and microbiota dysbiosis in Lateolabrax maculatus juveniles (9.37 ± 0.03 g) fed with high-carbohydrate diets. Six diets were designed: a control diet (20% corn starch, Control), high-carbohydrate diet (30% corn starch, HC1), and four high-carbohydrate diets supplemented with Rhodiola rosea L. at 30, 60, 90 and 120 mg/kg (HC2, HC3, HC4 and HC5, respectively). Compared with the control group, the HC1 diet remarkably increased α-amylase, lipase, and chymotrypsin activities in the intestine (p < 0.05), as well as the mRNA levels of Claudin-15, NF-κB, TNF-α, IL-1β, and IL-8 (p < 0.05) and the relative abundance of Proteobacteria and Photobacterium in the intestine, which belong to the phylum and genus level, respectively. But the opposite trend was found in muscular thickness and villus lengths (p < 0.05), the mRNA levels of Occludin, ZO-1, and TGF-β (p < 0.05), at the level of phylum and genus level in the HC1 group, and the relative abundance of Firmicutes, Bacteroidetes, and Bacillus in the intestine compared with the control group. Intestinal chymotrypsin activity was significantly higher in the HC3 group and intestinal muscular thickness and villus lengths were also significantly higher in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). In addition, Occludin mRNA expression in the intestine was significantly increased in the HC2, HC4, and HC5 groups compared to the HC1 group. ZO-1 and TGF-β mRNA expression in the intestine were significantly increased in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). At the phylum level, the relative abundance of Firmicutes and Bacteroidetes was higher in the intestine in the HC2, HC3, HC4, and HC5 groups than that in the HC1 group. On the contrary, intestinal lipase and chymotrypsin activities were significantly decreased in the HC2 group compared to the HC1 group, respectively (p < 0.05). The Claudin-15, NF-κB, TNF-α, IL-1β, and IL-8 mRNA expression in the intestine were significantly decreased in the HC2, HC3, HC4, and HC5 groups compared to the HC1 group (p < 0.05). Besides, at the genus level, compared to the HC1 group, the relative abundance of Photobacterium in the intestine and the diversity of the intestinal microbiota in the HC2, HC3, HC4, and HC5 groups were all decreased. In conclusion, these results demonstrated that the addition of Rhodiola rosea L. in high-carbohydrate diets can improve intestinal digestive enzyme activities, inflammatory response and intestinal barrier-related gene expression, and microbiota dysbiosis in L. maculatus. The suitable supplemental level of Rhodiola rosea L. in high-carbohydrate diets of L. maculatus is 60 mg/kg.
Topics: Animals; Rhodiola; NF-kappa B; Tumor Necrosis Factor-alpha; Chymotrypsin; Dysbiosis; Interleukin-8; Occludin; Intestines; Diet; Microbiota; Fishes; Lipase; RNA, Messenger; Starch; Transforming Growth Factor beta; Animal Feed
PubMed: 38218423
DOI: 10.1016/j.fsi.2024.109362