-
Animal Nutrition (Zhongguo Xu Mu Shou... Sep 2023Several reports have revealed the vital role that probiotics play in fish growth and health. However, few works are available for host gut-derived probiotics on the...
Host gut-derived probiotics supplementation improves growth performance, serum and liver immunity, gut health, and resistive capacity against infection in hybrid grouper ( × ♂).
Several reports have revealed the vital role that probiotics play in fish growth and health. However, few works are available for host gut-derived probiotics on the growth, immunity, and gut microbiota of fish, especially in hybrid grouper (♀ × ♂) due to their isolation difficulty and functional verification. This study aimed at assessing 3 host gut-derived species' effects on the growth, immune and antioxidant-biochemical responses, haematological parameters, intestinal morphology, immune-related gene expression, gut microbiota, and disease resistance against in hybrid grouper. A total of 480 hybrid grouper (initial weight = 9.03 ± 0.02 g) were randomly allotted into 4 groups, namely, the group fed a basal diet without probiotic inclusion (control, B0), the group fed the basal diet with GPSAK4 (BV), the group fed the basal diet with GPSAK9 (BS), and the group fed the basal diet with GPSAK2 (BT) strains at 1.0 × 10 CFU/g. After a 6-week feeding trial, the results revealed significant improvements ( < 0.05) in the growth performance, whole fish-body proximate composition, blood haematological parameters, serum, liver, and intestinal biochemical indexes, intestinal morphology, and protection against . pathogen in the probiotic-treated groups compared with the untreated. Additionally, the expressions of intestinal tight junction genes (occludin and ), pro- and anti-inflammatory genes, including , , , , , , and , were upregulated ( < 0.05) after species administration. Host gut-derived supplementation shaped the gut microbiota by significantly increasing ( < 0.05) the relative abundance of Proteobacteria, Bacteroidetes, Actinobacteria (except the BS group), Acidobacteria (except the BT group), Cyanobacteria (except the BV and BT groups), and Verrucomicrobia phyla, as well as known beneficial genera (, , , 1 and 13, , and ), but significantly decreased ( < 0.05) the abundance of Firmicutes, Chloroflexi, and Fusobacteria phyla, and purported pathogenic genera ( and ) compared with the control group. Collectively, the results suggest that . GPSAK4, . GPSAK9 (especially this strain), . GPSAK2 dietary supplementation at 1.0 × 10 CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation, thus enhancing the assimilation and absorption of nutrients to boost fish growth, immunity, and disease resistance.
PubMed: 37448647
DOI: 10.1016/j.aninu.2023.05.005 -
Frontiers in Physiology 2023This study explored the role of replacing fish meal protein with fermented soybean meal (FSBM) protein on the growth performance and intestinal morphology, immunity, and...
This study explored the role of replacing fish meal protein with fermented soybean meal (FSBM) protein on the growth performance and intestinal morphology, immunity, and microbiota of the pearl gentian grouper (). Three isonitrogenous and isolipidic diets with increasing levels of FSBM (0%, 20% and 40%; referred to as FM, FSBM20 and FSBM40 diets, respectively) as a replacement for fish meal were selected for this study. The pearl gentian grouper were fed these diets for 10 weeks. The findings revealed that the growth of fish fed the FSBM diets (FSBM20 and FSBM40) were remarkably lower than the fish fed the FM diet. Pathological manifestations of intestinal inflammation, such as shortened intestinal mucosal folds and thickened lamina propria, were observed in the fish fed the FSBM diets. Moreover, the gene expression levels of , , , and were remarkably upregulated in fish fed the FSBM40 diet, in contrast to the gene expression levels of and , which were remarkably downregulated ( < 0.05). The FSBM diets significantly affected the stability of the fish gut microbiota. was the dominant phylum in all experimental groups, and the proportion of these bacteria gradually decreased with increasing FSBM substitution. The composition of intestinal flora at the genus level was not the same in the three experimental groups, with a richer composition of intestinal bacteria detected in the FSBM20 and FSBM40 groups ( < 0.05). The correlation between intestinal flora balance and immune gene expression revealed that only was negatively correlated with the above upregulated genes, while other bacteria were positively correlated with these pro-inflammatory factors ( < 0.05). was positively correlated with the above downregulated genes, while other bacteria were negatively correlated with these anti-inflammatory factors ( < 0.05). In conclusion, high levels of substitution of FSBM for fish meal causes intestinal inflammation in pearl gentian grouper. This is likely associated with changes to the intestinal flora. More attention should be paid to the negative role of dietary FSBM on intestinal flora.
PubMed: 37469566
DOI: 10.3389/fphys.2023.1194071 -
International Journal of Food... Nov 2016The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have...
The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have identified major contamination routes of important spoilage associated species within the genera Pseudomonas, Shewanella and Photobacterium in pre-rigor processing of salmon. Bacterial counts and culture-independent 16S rRNA gene analysis on salmon fillet from seven processing plants showed higher levels of Pseudomonas spp. and Shewanella spp. in industrially processed fillets compared to salmon processed under strict hygienic conditions. Higher levels of Pseudomonas spp. and Shewanella spp. were found on fillets produced early on the production day compared to later processed fillets. The levels of Photobacterium spp. were not dependent on the processing method or time of processing. In follow-up studies of two plants, bacterial isolates (n=2101) from the in-plant processing environments (sanitized equipment/machines and seawater) and from salmon collected at different sites in the production were identified by partial 16S rRNA gene sequencing. Pseudomonas spp. dominated in equipment/machines after sanitation with 72 and 91% of samples from the two plants being Pseudomonas-positive. The phylogenetic analyses, based on partial 16S rRNA gene sequencing, showed 48 unique sequence profiles of Pseudomonas of which two were dominant. Only six profiles were found on both machines and in fillets in both plants. Shewanella spp. were found on machines after sanitation in the slaughter department while Photobacterium spp. were not detected after sanitation in any parts of the plants. Shewanella spp. and Photobacterium spp. were found on salmon in the slaughter departments. Shewanella was frequently present in seawater tanks used for bleeding/short term storage. In conclusion, this study provides new knowledge on the processing environment as a source of contamination of salmon fillets with Pseudomonas spp. and Shewanella spp., while Photobacterium spp. most likely originate from the live fish and seawater. The study show that strict hygiene during processing is a prerequisite for optimal shelf life of salmon fillets and that about 90% reductions in the initial levels of bacteria on salmon fillets can be obtained using optimal hygienic conditions.
Topics: Animals; Bacterial Load; Fish Products; Food Contamination; Food Handling; Food Industry; Food Microbiology; Food Preservation; Norway; Photobacterium; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Salmon; Seawater; Shewanella
PubMed: 27552347
DOI: 10.1016/j.ijfoodmicro.2016.08.016 -
Frontiers in Microbiology 2021Chondroitin sulfate (CS)/dermatan sulfate (DS) is a kind of sulfated polyanionic, linear polysaccharide belonging to glycosaminoglycan. CS/DS sulfatases, which...
Chondroitin sulfate (CS)/dermatan sulfate (DS) is a kind of sulfated polyanionic, linear polysaccharide belonging to glycosaminoglycan. CS/DS sulfatases, which specifically hydrolyze sulfate groups from CS/DS oligo-/polysaccharides, are potential tools for structural and functional studies of CD/DS. However, only a few sulfatases have been reported and characterized in detail to date. In this study, two CS/DS sulfatases, PB_3262 and PB_3285, were identified from the marine bacterium sp. QA16 and their action patterns were studied in detail. PB_3262 was characterized as a novel 4--endosulfatase that can effectively and specifically hydrolyze the 4--sulfate group of disaccharide GlcUAβ1-3GalNAc(4--sulfate) but not GlcUAβ1-3GalNAc(4,6--sulfate) and IdoUAα1-3GalNAc(4--sulfate) in CS/DS oligo-/polysaccharides, which is very different from the identified 4--endosulfatases in the substrate profile. In contrast, PB_3285 specifically hydrolyzes the 6--sulfate groups of GalNAc(6--sulfate) residues located at the reducing ends of the CS chains and is the first recombinantly expressed 6--exosulfatase to effectively act on CS oligosaccharides.
PubMed: 35140691
DOI: 10.3389/fmicb.2021.775124 -
Journal of Fish Diseases Jul 2020Photobacteriosis, caused by Photobacterium damselae subsp. piscicida (Phdp), is a serious disease in marine fish species worldwide. To date, the epidemiological...
Photobacteriosis, caused by Photobacterium damselae subsp. piscicida (Phdp), is a serious disease in marine fish species worldwide. To date, the epidemiological characterization of this pathogen in Taiwan remains limited. In this study, we collected 39 Phdp isolates obtained from different farmed fish for phenotypic and genotypic analysis. Phenotype bioassays using API-20E and API-20NE systems showed that the Phdp is a homogeneous group. However, genotyping using the pulsed-field gel electrophoresis (PFGE) technique revealed genetic variability among Phdp isolates when 13 and 11 different PFGE band patterns were obtained with SmaI and NotI as restriction enzymes, respectively. Phylogenetic analysis using 16S rDNA and the Fur gene clustered Taiwanese isolates and other species of P. damselae in the same clade. In contrast, the ToxR phylogenetic tree, a powerful discriminatory marker, separated the two subspecies. Furthermore, the virulence-associated genes, AIP56, P55, PDP_0080, Sod and Irp1, were detected from all isolates. Virulence testing with nine representative isolates in cobia (Rachycentron canadum) and Asian sea bass (Lates calcarifer) showed that some were highly pathogenic with 80%-100% mortality rates. This study provides epidemiological data of Phdp infections in farmed fish in Taiwan, which is necessary to develop comprehensive prevention and control strategies for the disease.
Topics: Animals; Fish Diseases; Fishes; Genetic Variation; Genotype; Gram-Negative Bacterial Infections; Phenotype; Photobacterium; Phylogeny; Taiwan; Virulence
PubMed: 32419196
DOI: 10.1111/jfd.13173 -
Foods (Basel, Switzerland) Jul 2021Improved quality control and prolonged shelf life are important actions in preventing food waste. To get an overview of the bacterial diversity of fillets from live...
Improved quality control and prolonged shelf life are important actions in preventing food waste. To get an overview of the bacterial diversity of fillets from live stored mature Atlantic cod, bacterial isolates were identified before and after storage (air and vacuum) and freezing/thawing. Based on the load of dominating bacteria, the effect of different packaging methods and a short freezing/thawing process on prolonged shelf-life was evaluated (total viable counts, bacteriota, sensory attributes, and volatile components). Hand filleted (strict hygiene) cod fillets had a low initial bacterial load dominated by the spoilage organism , whereas industrially produced fillets had higher bacterial loads and diversity (, , , ). The identified bacteria after storage in vacuum or air were similar to the initially identified bacteria. Bacteriota analysis showed that a short time freezing/thawing process reduced while modified atmosphere packaging (MAP; 60% CO/40% O or 60% CO/40% N) inhibited the growth of important spoilage bacteria () and allowed the growth of / and Despite being dominated by fresh fillets stored in MAP 60% CO/40% N demonstrated better sensory quality after 13 days of storage than fillets stored in MAP 60% CO/40% O (dominated by ). spp. or other members of may therefore be potential spoilage organisms in cod when other spoilage bacteria are reduced or inhibited.
PubMed: 34441531
DOI: 10.3390/foods10081754 -
International Journal of Molecular... Mar 2023Lumazine protein from marine luminescent bacteria of species bind with very high affinity to the fluorescent chromophore 6,7-dimethyl-8-ribitylumazine. The light...
Lumazine protein from marine luminescent bacteria of species bind with very high affinity to the fluorescent chromophore 6,7-dimethyl-8-ribitylumazine. The light emission of bacterial luminescent systems is used as a sensitive, rapid, and safe assay for an ever-increasing number of biological systems. Plasmid pRFN4, containing the genes encoding riboflavin from the operon of , was designed for the overproduction of lumazine. To construct fluorescent bacteria for use as microbial sensors, novel recombinant plasmids (pRFN4-Pp N-P and pRFN4-Pp LP N-P) were constructed by amplifying the DNA encoding the N-P gene (L) from and the promoter region (LP) present upstream of the operon of the gene by PCR and ligating into the pRFN4-Pp N-P plasmid. A new recombinant plasmid, pRFN4-Pp LP-N-P, was constructed with the expectation that the fluorescence intensity would be further increased when transformed into . When this plasmid was transformed into 43R, the fluorescence intensity of transformants was 500 times greater than that of alone. As a result, the recombinant plasmid in which the gene encoding N-LumP and DNA containing the promoter exhibited expression that was so high as to show fluorescence in single cells. The fluorescent bacterial systems developed in the present study using and riboflavin genes can be utilized in the future as biosensors with high sensitivity and rapid analysis times.
Topics: Escherichia coli; Riboflavin; Plasmids; Promoter Regions, Genetic; Operon; Luminescent Measurements; Bacterial Proteins
PubMed: 36982169
DOI: 10.3390/ijms24065096 -
International Journal of Molecular... Mar 2023subsp. () is a Gram-negative fish pathogen with worldwide distribution and broad host specificity that causes heavy economic losses in aquaculture. Although was first...
subsp. () is a Gram-negative fish pathogen with worldwide distribution and broad host specificity that causes heavy economic losses in aquaculture. Although was first identified more than 50 years ago, its pathogenicity mechanisms are not completely understood. In this work, we report that secretes large amounts of outer membrane vesicles (OMVs) when cultured in vitro and during in vivo infection. These OMVs were morphologically characterized and the most abundant vesicle-associated proteins were identified. We also demonstrate that OMVs protect cells from the bactericidal activity of fish antimicrobial peptides, suggesting that secretion of OMVs is part of the strategy used by to evade host defense mechanisms. Importantly, the vaccination of sea bass () with adjuvant-free crude OMVs induced the production of anti- antibodies and resulted in partial protection against infection. These findings reveal new aspects of biology and may provide a basis for developing new vaccines against this pathogen.
Topics: Animals; Bass; Photobacterium; Virulence; Vaccines; Fish Diseases; Gram-Negative Bacterial Infections
PubMed: 36982212
DOI: 10.3390/ijms24065138 -
Foods (Basel, Switzerland) Jul 2023Broomcorn millet Huangjiu brewing is usually divided into primary fermentation and post-fermentation. Microbial succession is the major factor influencing the...
Broomcorn millet Huangjiu brewing is usually divided into primary fermentation and post-fermentation. Microbial succession is the major factor influencing the development of the typical Huangjiu flavor. Here, we report the changes in flavor substances and microbial community during the primary fermentation of broomcorn millet Huangjiu. Results indicated that a total of 161 volatile flavor compounds were measured during primary fermentation, and estragole was detected for the first time in broomcorn millet Huangjiu. A total of 82 bacteria genera were identified. , , and were the dominant genera. and were dominant among the 30 fungal genera. Correlation analysis showed that 102 microorganisms were involved in major flavor substance production during primary fermentation, , , , , , , , and were most associated with flavoring substances. Four bacteria, (R1), (R2), (R3), and (R4), were isolated and identified from wheat Qu, which were added to wine Qu to prepare four kinds of fortified Qu (QR1, QR2, QR3, QR4). QR1 and QR2 fermentation can enhance the quality of Huangjiu. This work reveals the correlation between microorganisms and volatile flavor compounds and is beneficial for regulating the micro-ecosystem and flavor of the broomcorn millet Huangjiu.
PubMed: 37509772
DOI: 10.3390/foods12142680 -
Microbial Pathogenesis Oct 2016Photobacterium damselae is a Gram negative bacterium causes photobacteriosis, a worldwide septicemic disease in aquaculture including sea bass (Dicentrarchus labrax) and...
Photobacterium damselae is a Gram negative bacterium causes photobacteriosis, a worldwide septicemic disease in aquaculture including sea bass (Dicentrarchus labrax) and sea bream (Sparus aurata). The pathogenicity of bacterial subspecies and the disease pathological changes in natural and experimental infections have thus far yielded inconsistency of effective preventive measures. This study aimed to represent a comprehensive analysis of the potential pathogenic capacities of the two subspecies of P. damselae in cultured sea bass and sea bream in the Northwestern region of Egypt. Diseased 321 sea bass and 257 sea bream, in addition to 99 healthy sea bass fingerlings were sampled from three farms located along the Mediterranean Sea. P. damselae subspecies were isolated from diseased fish and characterized using bacteriological, molecular, and antimicrobial susceptibility methods. Healthy fish were challenged by a virulent P. damselae subsp. piscicida, monitored for disease signs and mortality, and the histopathological abnormalities and hematological disorders were carried out. Clinical signs and gross lesions in naturally infected sea bass and sea bream showed great similarities with absence of a subspecies-specific characteristic sign or lesion. The two subspecies were recovered through the entire year from individual fish sample, suggests a coexistence of two subspecies endemic infection. In diseased sea bass, 38.32% and 16.20% were positive for P. damselae subsp. piscicida and subsp. damselae, respectively. However in diseased sea bream, 44.47% and 26.46% were positive for P. damselae subsp. piscicida and subsp. damselae, respectively. High mortalities and devastating clinicopathologic abnormalities represented by sever clinical signs, hematological disorders and histological abnormalities strengthen the pathogenicity of P. damselae subspecies in the two fish species and therefore, a vaccination strategy against both subspecies should be taken into account.
Topics: Animals; Aquaculture; Bass; Egypt; Fish Diseases; Gram-Negative Bacterial Infections; Histocytochemistry; Mediterranean Sea; Photobacterium; Sea Bream; Survival Analysis
PubMed: 27497892
DOI: 10.1016/j.micpath.2016.08.003