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Frontiers in Microbiology 2022Lake Cajititlán is a subtropical and endorheic lake, which is heavily impacted by nutrient pollution. Agricultural runoff and poorly treated wastewater have entered...
Lake Cajititlán is a subtropical and endorheic lake, which is heavily impacted by nutrient pollution. Agricultural runoff and poorly treated wastewater have entered this reservoir at alarming rates during past rainy seasons, causing the cultural eutrophication of this body of water and resulting in several massive fish kill events. In this study, shotgun metagenomic sequencing was used to examine the taxonomic and functional structure of microbial communities in Lake Cajititlán during the rainy season. Several water quality features and their interactions with microbial communities were also assessed to identify the major factors affecting the water quality and biota, specifically fish species. According to current water quality regulations, most of the physicochemical variables analyzed (dissolved oxygen, pH, Secchi disk, NH , NO , blue-green algae, total phosphorus, and chlorophyll-) were outside of the permissible limits. and were the most abundant phytoplankton species, and the dominant bacterial genera were , , and , with , , and representing the most abundant bacterial species. All of these microorganisms have been reported to be potentially harmful to fish, and the latter three (, , ) also contain genes associated with pathogenicity in fish mortality (, S, , , , , , ). Genetic evidence from the microbial communities analyzed herein reveals that anthropogenic sources of nutrients in the lake altered genes involved in nitrogen, phosphorus, sulfur, and carbon metabolism, mainly at the beginning of the rainy season. These findings suggest that abiotic factors influence the structure of the microbial communities, along with the major biogeochemical cycles of Lake Cajititlán, resulting in temporal variations and an excess of microorganisms that can thrive in high-nutrient and low-oxygen environments. After reviewing the literature, this appears to be the first study that focuses on characterizing the water quality of a subtropical hypereutrophic lake through associations between physicochemical variables and shotgun metagenomic data. In addition, there are few studies that have coupled the metabolism of aquatic ecosystems with nutrient cycles.
PubMed: 36532453
DOI: 10.3389/fmicb.2022.1037626 -
Frontiers in Immunology 2022are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic...
are autochthonous bacteria of aquatic environments that are considered to be emerging pathogens to humans, producing diarrhea, bacteremia, and wound infections. Genetic identification shows that 95.4% of the strains associated with clinical cases correspond to the species (37.26%), (23.49%), (21.54%), and (13.07%). However, few studies have investigated the human immune response against some spp. such as , , and . The present study aimed to increase the knowledge about the innate human immune response against six species, using, for the first time, an infection model with the monocytic human cell line THP-1, and to evaluate the intracellular survival, the cell damage, and the expression of 11 immune-related genes (, , , , , , , , , , and ). Transcriptional analysis showed an upregulated expression of a variety of the monocytic immune-related genes, with a variable response depending upon the species. The species that produced the highest cell damage, independently of the strain origin, coincidentally induced a higher expression of immune-related genes and corresponded to the more prevalent clinical species , , and . Additionally, monocytic cells showed an overexpression of the apoptotic and pyroptotic genes involved in cell death after , , and infection. However, the apoptosis route seemed to be the only way of producing cell damage and death in the case of the species and , while apparently only used the pyroptosis route.
Topics: Aeromonas; Aeromonas hydrophila; Cell Line; Gram-Negative Bacterial Infections; Humans; Immunity
PubMed: 35874671
DOI: 10.3389/fimmu.2022.875689 -
Ecotoxicology and Environmental Safety Aug 2021Cherax quadricarinatus is a type of large freshwater crayfish that is characterized by rapid growth and formidable adaptability. It has also been widely cultured and...
A new insight to characterize immunomodulation based on hepatopancreatic transcriptome and humoral immune factor analysis of the Cherax quadricarinatus infected with Aeromonas veronii.
Cherax quadricarinatus is a type of large freshwater crayfish that is characterized by rapid growth and formidable adaptability. It has also been widely cultured and studied as a model organism. Aeromonas veronii is the dominant pathogen in aquatic environments and the primary threat to aquaculture's economic stability. To better understand the interactions between C. quadricarinatus and A. veronii, high-throughput RNA sequencing of the C. quadricarinatus hepatopancreas was carried out on a control group, susceptible group (6 h after infection), and resistant group (48 h after infection). A total of 65,850,929 genes were obtained. Compared with the control group, 2616 genes were up-regulated and 1551 genes were down-regulated in the susceptible group; while 1488 genes were up-regulated and 1712 genes were down-regulated in the resistant group. GO and KEGG analysis showed that these differentially expressed genes (DEGs) were associated with multiple immune pathways, including Toll-like receptors (TLRs), antigen processing and presentation, NOD-like receptor signaling pathway, phagosome, lysosome, JAK-STAT signaling pathway. qRT-PCR showed that infection by A. veronii changed the expression pattern of the serine proteinase inhibitor (SPI), crustacean hyperglycemic hormone (CHH), anti-lipopolysaccharide factor (ALF), and extracellular copper/zinc superoxide dismutase (SOD1), all of which were significantly higher than in the control group up to 48 h after infection. In addition, detection of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and phenoloxidase (PO) activity, as well as ceruloplasmin (CP) concentration at different times after infection showed diverse trends. Furthermore, pathological sections obtained 24 h after infection show lesions on the hepatopancreas and intestinal tissues caused by A. veronii. The results of this study provide a foundation for analyzing the immune mechanism of C. quadricarinatus infected with A. veronii at the transcriptional level and a theoretical basis for screening disease-resistant individuals to ensure healthy economic development of the aquatic industry.
Topics: Aeromonas veronii; Animals; Astacoidea; Factor Analysis, Statistical; Gram-Negative Bacterial Infections; Hepatopancreas; High-Throughput Nucleotide Sequencing; Immunologic Factors; Immunomodulation; Toll-Like Receptors; Transcriptome
PubMed: 34044307
DOI: 10.1016/j.ecoenv.2021.112347 -
Journal of Aquatic Animal Health Sep 2021One of the major goals in aquaculture is to protect fish against infectious diseases as disease outbreaks could lead to economic losses if not controlled. Antimicrobial...
One of the major goals in aquaculture is to protect fish against infectious diseases as disease outbreaks could lead to economic losses if not controlled. Antimicrobial peptides (AMPs), a class of highly conserved peptides known to possess direct antimicrobial activities against invading pathogens, were evaluated for their ability to protect Channel Catfish Ictalurus punctatus and hybrid catfish (female Channel Catfish × male Blue Catfish I. furcatus) against infection caused by the fish pathogen Aeromonas hydrophila ML09-119. To identify effective peptides, the minimum inhibitory concentrations against bacterial pathogens Edwardsiella ictaluri S97-773, Edwardsiella piscicida E22-10, A. hydrophila ML09-119, Aeromonas veronii 03X03876, and Flavobacterium columnare GL-001 were determined in vitro. In general and overall, cathelicidins derived from alligator and sea snake exhibited more potent and rapid antimicrobial activities against the tested catfish pathogens as compared to cecropin and pleurocidin AMPs and ampicillin, the antibiotic control. When the peptides (2.5 µg of peptide/g of fish) were injected into fish and simultaneously challenged with A. hydrophila through immersion, increased survival rates in Channel Catfish and hybrid catfish were observed in both cathelicidin (alligator and sea snake) treatments as compared to other peptides and the infected control (P < 0.001) with alligator cathelicidin being the overall best treatment. Bacterial numbers in the kidney and liver of Channel Catfish and hybrid catfish also decreased (P < 0.05) for cathelicidin-injected groups at 24 and 48 h after challenge infection. These results show the potential of cathelicidin to protect catfish against bacterial infections and suggest that an approach overexpressing the peptide in transgenic fish, which is the long-term goal of this research program, may provide a method of decreasing bacterial disease problems in catfish as delivering the peptides via individual injection or feeding would not be economically feasible.
Topics: Animals; Antimicrobial Cationic Peptides; Catfishes; Edwardsiella; Female; Fish Diseases; Flavobacterium; Ictaluridae; Male; Cathelicidins
PubMed: 34121235
DOI: 10.1002/aah.10131 -
International Journal of Molecular... Dec 2020is one of the main pathogens causing various diseases in humans and animals. It is currently difficult to eradicate drug-resistant due to the biofilm formation by...
is one of the main pathogens causing various diseases in humans and animals. It is currently difficult to eradicate drug-resistant due to the biofilm formation by conventional antibiotic treatments. In this study, a marine peptide-N6NH and its analogs were generated by introducing Orn or replacing with D-amino acids, Val and Pro; their enzymic stability and antibacterial/antibiofilm ability against multi-drug resistant (MDR) ACCC61732 were detected in vitro and in vivo, respectively. The results showed that DN6NH more rapidly killed ACCC61732 and had higher stability in trypsin, simulated gastric/intestinal fluid, proteinase K, and mouse serum than the parent peptide-N6NH. DN6NH and other analogs significantly improved the ability of N6NH to penetrate the outer membrane of ACCC61732. DN6NH, N6PNH and V112N6NH protected mice from catheter-associated biofilm infection with MDR ACCC61732, superior to N6NH and CIP. DN6NH had more potent efficacy at a dose of 5 μmol/kg (100% survival) in a mouse peritonitis model than other analogs (50-66.67%) and CIP (83.33%), and it inhibited the bacterial translocation, downregulated pro-inflammatory cytokines, upregulated the anti-inflammatory cytokine, and ameliorated multiple-organ injuries (including the liver, spleen, lung, and kidney). These data suggest that the analogs of N6NH may be a candidate for novel antimicrobial and antibiofilm agents against MDR infections.
Topics: Aeromonas veronii; Animals; Anti-Bacterial Agents; Biofilms; Drug Resistance, Multiple; Female; Gram-Negative Bacterial Infections; Mice; Mice, Inbred ICR; Microbial Sensitivity Tests; Multiple Organ Failure; Skin Ulcer
PubMed: 33348848
DOI: 10.3390/ijms21249637 -
Microbiological Research Sep 2021Bacillus amyloliquefaciens X030 (BaX030) has broad-spectrum antibacterial activity against the fish pathogens Aeromonas hydrophila and Aeromonas veronii. To improve its...
Bacillus amyloliquefaciens X030 (BaX030) has broad-spectrum antibacterial activity against the fish pathogens Aeromonas hydrophila and Aeromonas veronii. To improve its antibacterial effect, BaX030 was subjected to compound mutagenesis of atmospheric and room temperature plasma (ARTP) and nitrosoguanidine (NTG). The results showed that, compared with the original strain, the production of macrolactin A and oxydifficidin in mutated strain N-11 increased to 39 % and 268 %, respectively. The re-sequencing analysis suggested that there were SNPs and InDels in the gene clusters focused on the sucrose utilization pathway, glycolysis pathway and fatty acid synthesis pathway. Scanning electron microscopy revealed that strain N-11 became thin and long. The qRT-PCR results indicated that the expression of immune factors in the liver or kidney tissue of grass carp increased after feeding with N-11. H&E staining and protection experiments also showed that the mortality and surface symptoms of grass carp infected by the two pathogens were significantly reduced. The study identified a probiotic strain with potential application value in aquaculture production and provided a new strategy for the discovery of new strains with higher antibacterial biological activity.
Topics: Aeromonas hydrophila; Aeromonas veronii; Animals; Bacillus amyloliquefaciens; Carps; Fish Diseases; Microbial Interactions; Mutation; Probiotics
PubMed: 34139525
DOI: 10.1016/j.micres.2021.126801 -
Fish & Shellfish Immunology Aug 2021The heavy use of prophylactic antibiotics in aquaculture leads to elevated antibiotic residues, posing a huge hidden danger in aquaculture products and other natural...
The heavy use of prophylactic antibiotics in aquaculture leads to elevated antibiotic residues, posing a huge hidden danger in aquaculture products and other natural aquatic environments. Therefore, this study aims to isolate probiotics that can replace antibiotics from the gut of grass carp for disease control. Bacillus velezensis B8 was isolated from the gut of grass carp and showed broad-spectrum antimicrobial activity against several fish pathogenic bacteria, including Aeromonas hydrophilis, Aeromonas veronii, Vibrio parahaemolyticus, Escherichia coli, Edwardsiella tarda and Vibrio mimicus. The safety evaluation showed that the strain B8 was non-toxic to grass carp, had no hemolytic activity, and was sensitive to most antibiotics. In vitro study indicated that strain B8 was viable at pH 2-7, had weak tolerance to 0.1% (w/v) bile salt, and could grow at 10°C-40 °C. The grass carps were fed with diets containing 0 (control), 10, and 10 cfu/g of strain B8 for 4 weeks. Various immune parameters were measured at 1, 2, 3, and 4 weeks of post-feeding. The results of non-specific immunoassay showed that diets supplemented with B8 significantly increased alkaline phosphatase (AKP) and superoxide dismutase (SOD) activity in serum samples (p < 0.05). The expression levels of immune-related genes in the kidney and spleen of grass carp were measured. Among them, the expression levels of IgM and TNF-α both in spleen and kidney were significantly increased after 3 and 4 weeks of post-feeding (p < 0.05). The expression of IgD and MHCI in kidney was significantly upregulated in high-dose groups after 2 and 3 weeks of feeding, respectively (p < 0.05). In addition, after 7 days of challenging with A. veronii, the high-dose group and low-dose group had 48% and 53% survival compared to 25% survival for the control group. These results suggest that B. velezensis B8 has the potential to be developed into a microecological preparation for the alternatives of antibiotics in aquaculture.
Topics: Aeromonas veronii; Animal Feed; Animals; Bacillus; Carps; Diet; Disease Resistance; Dose-Response Relationship, Drug; Fish Diseases; Gram-Negative Bacterial Infections; Immunity, Innate; Probiotics; Random Allocation
PubMed: 34015480
DOI: 10.1016/j.fsi.2021.05.012 -
Journal of Fish Diseases Feb 2024Aeromonas septicemia still represents a serious challenge facing the global aquaculture sector. In the present study, Aeromonas caviae and A. veronii were isolated from...
Aeromonas septicemia still represents a serious challenge facing the global aquaculture sector. In the present study, Aeromonas caviae and A. veronii were isolated from four diseased European seabass (Dicentrarchus labrax) farms experiencing a high mortality rate. Diseased fish showed haemorrhages on the external body surface with exophthalmia, cataracts, scale desquamation, skin ulcers and fin erosions. The most common post-mortem findings were congested internal organs, particularly the liver and posterior kidney. Twenty-eight A. Veronii and 11 A. caviae isolates were identified biochemically by the Vitek 2 system and then confirmed by PCR and phylogenetic analysis. Hemolysin (hlyA) and aerolysin (aer) were the most abundant virulence genes in the recovered isolates, followed by cytotoxic enterotoxin (act) and heat-stable enterotoxin (ast). A. caviae was more virulent than A. veronii for D. labrax fingerlings as LD ranging between (>1 × 10 -6.2 × 10 ) for A. veronii and (2.9 × 10 -8.3 × 10 ) for A. caviae. The sensitivity test indicated the effectiveness of norfloxacin, doxycycline and oxytetracycline against the tested isolates. Serum cortisol significantly increased in the infected groups, while catalase and glutathione peroxidase activities significantly decreased at 2 days post-infection (DPI) and then increased at 6 DPI. The presence of virulence genes was associated with bacterial pathogenicity expressed in fish mortality rate. Virulence genes also drastically affect cortisol levels more than catalase and glutathione peroxidase levels.
Topics: Animals; Aeromonas; Virulence; Bass; Catalase; Genotype; Phylogeny; Hydrocortisone; Fish Diseases; Enterotoxins; Glutathione Peroxidase; Gram-Negative Bacterial Infections
PubMed: 37881027
DOI: 10.1111/jfd.13878 -
Fish Physiology and Biochemistry Aug 2023In this study, the effects of Coriandrum sativum to control Aeromonas veronii infection in Oreochromis niloticus were determined. Coriandrum sativum extract (CE) was...
Therapeutic efficacy of coriander (Coriandrum sativum) enriched diets in Oreochromis niloticus: effect on hepatic-renal functions, the antioxidant-immune response and resistance to Aeromonas veronii.
In this study, the effects of Coriandrum sativum to control Aeromonas veronii infection in Oreochromis niloticus were determined. Coriandrum sativum extract (CE) was tested in vitro against A. veronii by the disc diffusion assay. In in vivo, 150 O. niloticus (from El-Abbassa, Sharkia, Egypt, weighing 34.95 ± 1.98 g) was distributed in five groups (with three replications) in glass aquariums (80 × 40 × 30 cm). The first group (control) was intraperitoneally injected with 0.2 ml of sterilized tryptic soya broth. Groups 2-5 were intraperitoneally challenged with 0.2 ml of A. veronii (4.3 × 10). The five groups were administered a basal diet until clinical signs appeared, and then therapeutic feeding (15 days) was followed: the first (CONT) and second (AV) groups were administered a normal basal diet. The third (AV+CP) and fourth (AV+CE) groups were administered diets supplemented with C. sativum powder and extract, respectively, each at 30 mg/kg. The fifth group (AV+OT) was administered a diet supplemented with oxytetracycline at 500 mg/kg diet. The results of the in vitro experiment revealed that CE has a zone of inhibition of 43 mm against A. veronii. The in vivo results showed that fish administered a therapeutic diet supplemented with CE showed a significant improvement in hematological, biochemical, and immunological parameters, as well as antioxidant capacity (P < 0.05) and the pathological findings of the liver and kidney tissues. The current findings supported that the administration of a CE-enriched diet (30 mg/kg) is an eco-friendly strategy for controlling A. veronii in O. niloticus.
Topics: Animals; Antioxidants; Aeromonas veronii; Coriandrum; Cichlids; Diet; Dietary Supplements; Disease Resistance; Kidney; Fish Diseases; Animal Feed; Gram-Negative Bacterial Infections
PubMed: 37438674
DOI: 10.1007/s10695-023-01220-6 -
Journal of Applied Microbiology Apr 2024Although elasmobranchs are consumed worldwide, bacteriological assessments for this group are still sorely lacking. In this context, this study assessed bacteria of...
AIMS
Although elasmobranchs are consumed worldwide, bacteriological assessments for this group are still sorely lacking. In this context, this study assessed bacteria of sharks and rays from one of the most important landing ports along the Rio de Janeiro coast.
METHODS AND RESULTS
Bacteria were isolated from the cloacal swabs of the sampled elasmobranchs. They were cultured, and Vibrio, Aeromonas, and Enterobacterales were isolated and identified. The isolated bacteria were then biochemically identified and antimicrobial susceptibility assays were performed. Antigenic characterizations were performed for Salmonella spp. and Polymerase Chain Reaction (PCR) assays were performed to identify Escherichia coli pathotypes. Several bacteria of interest in the One Health context were detected. The most prevalent Enterobacterales were Morganella morganii and Citrobacter freundii, while Vibrio harveyi and Vibrio fluvialis were the most prevalent among Vibrio spp. and Aeromonas allosacharophila and Aeromonas veronii bv. veronii were the most frequent among Aeromonas spp. Several bacteria also displayed antimicrobial resistance, indicative of Public Health concerns. A total of 10% of Vibrio strains were resistant to trimethoprim-sulfamethoxazole and 40% displayed intermediate resistance to cefoxitin. Salmonella enterica strains displayed intermediate resistance to ciprofloxacin, nalidixic acid and streptomycin. All V. cholerae strains were identified as non-O1/non-O139. The detected E. coli strains did not exhibit pathogenicity genes. This is the first study to perform serology assessments for S. enterica subsp. enterica isolated from elasmobranchs, identifying the zoonotic Typhimurium serovar. Salmonella serology evaluations are, therefore, paramount to identify the importance of elasmobranchs in the epidemiological salmonellosis chain.
CONCLUSIONS
The detection of several pathogenic and antibiotic-resistant bacteria may pose significant Public Health risks in Brazil, due to high elasmobranch consumption rates, indicating the urgent need for further bacteriological assessments in this group.
Topics: Animals; Escherichia coli; Sharks; Brazil; Salmonella; Vibrio cholerae; Anti-Bacterial Agents; Aeromonas
PubMed: 38486350
DOI: 10.1093/jambio/lxae068