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Applied and Environmental Microbiology Oct 2006Eighty-one tetracycline-resistant Aeromonas sp. strains were isolated from farm-raised catfish. Morphological and biochemical characteristics indicated that 23 of the 81...
Eighty-one tetracycline-resistant Aeromonas sp. strains were isolated from farm-raised catfish. Morphological and biochemical characteristics indicated that 23 of the 81 aeromonads were Aeromonas hydrophila, 7 isolates were Aeromonas trota, 6 isolates were Aeromonas caviae, 42 isolates were Aeromonas veronii, and 3 isolates were Aeromonas jandaei. However, the AluI and MboI restriction fragment length polymorphism (RFLP) patterns of the PCR-amplified 1.4-kb 16S rRNA gene from all 81 tetracycline-resistant aeromonads from catfish were identical to the RFLP banding patterns of A. veronii ATCC 35626, indicating that all 81 isolates were strains of A. veronii. A multiplex PCR assay successfully amplified the 5 tetracycline-resistant genes (tetA to E) from the genomic DNA of all 81 isolates. The assay determined that tetE was the dominant gene occurring in 73/81 (90.0%) of the aeromonads. Plasmids (2.0 to 20 kb) were isolated from 33 of the 81 isolates. Dendrogram analysis of the SpeI pulsed-field gel electrophoresis identified 15 distinct macrorestriction patterns among the isolates. Our results indicate the need for use of 16S rRNA in the identification of Aeromonas spp. and the prevalence of catfish as a reservoir of tet genes.
Topics: Aeromonas; Animals; Bacterial Typing Techniques; Catfishes; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Food Microbiology; Plasmids; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 16S; Tetracyclines
PubMed: 17021193
DOI: 10.1128/AEM.00271-06 -
Veterinary World May 2020The present study aimed at highlighting the effects of oyster mushroom (), as a dietary supplement on growth performance, differential leukocytes population, and...
AIM
The present study aimed at highlighting the effects of oyster mushroom (), as a dietary supplement on growth performance, differential leukocytes population, and histological changes of melanomacrophage centers (MMCs) in spleen and kidney of fancy carp on bacterial infection.
MATERIALS AND METHODS
A total of 60 fancy carp were allocated into four groups according to feed formulations including; (1) basal diet with 2% crude extract of , (2) basal diet with 2% b-glucan, whereas Group 3, and Group 4 were positive and negative control, which were fed only basal diet. Diets were provided for 30 days, thereafter, fish of Group 1 to Group 3 were intraperitoneally injected with (1.8×10 CFU), whereas Group 4 was injected with normal saline. At day 7 post-bacterial inoculation, all fish were weighed, whole blood was collected for differential white blood cell count, and two visceral organs, posterior kidney and spleen, were collected from euthanized fish to observe histological changes, particularly MMCs.
RESULTS
No significant differences in body weight were found (p>0.05) at 1 week of the experiment; however, fish body weight was significantly increased from week 2 to week 4 of the experiment. Increased monocyte number was found in carp fish fed with the or b-glucan supplemented diets compared to the control groups (p<0.05). The proliferation of monocyte in fish was consistent with increased number and size of MMCs in hemotopoietic organs, posterior kidney and spleen, especially in fancy carp fed with of crude extract and commercially available b-glucan before bacterial inoculation in fish.
CONCLUSION
These findings indicate that crude polysaccharide from . can be potentially used as a feed additive that might promote innate immune function in fish.
PubMed: 32636602
DOI: 10.14202/vetworld.2020.1010-1016 -
Oxidative Medicine and Cellular... 2022Our previous studies demonstrated that melatonin could effectively ameliorate sleep deprivation- (SD-) caused oxidative stress-mediated gut microbiota disorder and...
BACKGROUND
Our previous studies demonstrated that melatonin could effectively ameliorate sleep deprivation- (SD-) caused oxidative stress-mediated gut microbiota disorder and colitis. The research further clarified the mechanism of melatonin in improving colitis from the perspective of the interaction between and goblet cells.
METHODS
A seventy-two hours SD mouse model with or without melatonin intervention and fecal microbiota transplantation (FMT) to explore the vital position of -goblet cell interactions in melatonin improving SD-induced colitis. Moreover, or LPS-supplied mice were assessed, and the influence of melatonin on -goblet cell interactions-mediated oxidative stress caused colitis. Furthermore, in vitro experiment investigated the regulation mechanism of melatonin.
RESULTS
Our study showed that SD induced colitis, with upregulation of and LPS levels and reductions in goblet cells number and MUC2 protein. Similarly, FMT from SD mice, veronii colonization, and LPS treatment restored the SD-like goblet cells number and MUC2 protein decrease and colitis. Moreover, LPS treatment downregulated the colonic antioxidant capacity. Yet, melatonin intervention reversed all consequence in SD, veronii colonization, and LPS-treated mice. In vitro, melatonin reversed veronii- or LPS-induced MUC2 depletion in mucus-secreting human HT-29 cells via increasing the expression level of Villin, Tff3, p-GSK-3, -catenin, and melatonin receptor 2 (MT2) and decreasing the level of p-IB, p-P65, ROS, TLR4, and MyD88 proteins, while the improvement effect was blocked with pretreatment with a MT2 antagonist but were mimicked by TLR4 and GSK-3 antagonists and ROS scavengers.
CONCLUSIONS
Our results demonstrated that melatonin-mediated MT2 inhibits -goblet cell interactions to restore the level of MUC2 production via LPS/TLR4/MyD88/GSK-3/ROS/NF-B loop, further improving colitis in SD mice.
Topics: Aeromonas; Animals; Cell Communication; Colitis; Glycogen Synthase Kinase 3 beta; Goblet Cells; Melatonin; Mice; Sleep Deprivation
PubMed: 35355860
DOI: 10.1155/2022/8133310 -
Frontiers in Public Health 2021Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained...
Aeromonads are aquatic bacteria associated with frequent outbreaks of diarrhea in coastal Bangladesh, but their potential risks from environmental sources have remained largely unexplored. This study, over 2 years, examined homestead pond waters in the region for monthly dynamics and diversity of spp. The bacterial counts showed bi-modal annual growth peak, pre- and post-monsoon, strongly correlating ( < 0.0005) with temperature. Of 200 isolates characterized, bv. sobria (27%) was predominant among co-existent (20%), (17%), (13%), and three more. PCR screening of virulence-related genes identified 15 genotypes (I to XV), however, enterotoxigenicity in animal model was observed for five genotypes, ca. 18% (nine of 50) strains, prevalent in bv. sobria, , and . Pathogenic strains were distinguishable by possessing at least three of the major virulence genes: , and , together with accessory virulence factors. PFGE of I-digested genomic DNA revealed high genetic diversity and distant lineage of potentially toxigenic clones. Therefore, along with increased global warming, spp. having multi-factorial virulence potential in coastal ponds that serve as drinking water sources pose a potential health risk, and underscores the need for routine monitoring.
Topics: Aeromonas; Animals; Bangladesh; Ponds; Virulence; Water
PubMed: 34307285
DOI: 10.3389/fpubh.2021.692166 -
Journal of Clinical Microbiology Mar 1999Fifty-six isolates of four Aeromonas species, which have been documented as causative agents of human infections or isolated from human clinical specimens, were...
Fifty-six isolates of four Aeromonas species, which have been documented as causative agents of human infections or isolated from human clinical specimens, were subjected to antimicrobial susceptibility testing using a MicroScan WalkAway conventional (overnight incubation) gram-negative panel. The four species tested and the number of isolates of each were as follows: Aeromonas jandaei, 17; A. schubertii, 12; A. trota, 15; and A. veronii biotype veronii, 12. All isolates of A. trota were susceptible to all antimicrobial agents tested, except cefazolin (20% of isolates were resistant) and cefoxitin (13% of isolates were resistant). All isolates of A. schubertii and A. veronii biotype veronii, as well as 88% of A. jandaei isolates, were resistant to ampicillin. Resistance to ampicillin-sulbactam ranged from 25% of A. schubertii strains to 100% of A. veronii biotype veronii strains. Cefazolin resistance ranged from 17% of A. veronii biotype veronii isolates to 59% of A. jandaei isolates. Imipenem resistance was detected in 65% of A. jandaei strains and 67% of A. veronii biotype veronii strains. A. jandaei displayed resistance to piperacillin and ticarcillin in 53 and 71% of the isolates, respectively. A. veronii biotype veronii strains were 100% susceptible to piperacillin and 100% resistant to ticarcillin. These antibiogram data may be useful in establishing the identification of these four species when members of the genus Aeromonas are isolated from human clinical sources.
Topics: Aeromonas; Ampicillin Resistance; Anti-Bacterial Agents; Cefazolin; Cephalosporin Resistance; Gram-Negative Bacterial Infections; Humans; Microbial Sensitivity Tests; Serotyping
PubMed: 9986836
DOI: 10.1128/JCM.37.3.706-708.1999 -
Toxins Oct 2016ExoU, a type III secretory toxin and major virulence factor with patatin-like phospholipase activity, is responsible for acute lung injury and sepsis in... (Review)
Review
ExoU, a type III secretory toxin and major virulence factor with patatin-like phospholipase activity, is responsible for acute lung injury and sepsis in immunocompromised patients. Through use of a recently updated bacterial genome database, protein sequences predicted to be homologous to ExoU were identified in 17 other species (, , , , , , , , , , , , , , and ) and 8 Gram-negative bacteria from three other genera (, , and ). In the alignment of the predicted primary amino acid sequences used for the phylogenetic analyses, both highly conserved and nonconserved parts of the toxin were discovered among the various species. Further comparative studies of the predicted ExoU homologs should provide us with more detailed information about the unique characteristics of the ExoU toxin.
Topics: Animals; Bacterial Proteins; Bacterial Toxins; Gram-Negative Bacteria; Humans; Molecular Chaperones; Phospholipases
PubMed: 27792159
DOI: 10.3390/toxins8110307 -
Gut Microbes 2012Gastrointestinal microbiomes play important roles in the health and nutrition of animals and humans. The medicinal leech, Hirudo verbana, serves as a powerful model for... (Review)
Review
Gastrointestinal microbiomes play important roles in the health and nutrition of animals and humans. The medicinal leech, Hirudo verbana, serves as a powerful model for the study of microbial symbioses of the gut, due to its naturally limited microbiome compared with other popular models, the ability to cultivate the most abundant microbes, and genetically manipulate one of them, Aeromonas veronii. This review covers the relevance and application of leeches in modern medicine as well as recent discoveries detailing the nature of the gut microbiome. Additionally, the dual life-style of A. veronii allows one to do direct comparisons between colonization factors for beneficial and pathogenic associations, and relevant findings are detailed with respect to their role within the host and pathogenicity to other animals.
Topics: Aeromonas; Animals; Gastrointestinal Tract; Leeches; Symbiosis
PubMed: 22572874
DOI: 10.4161/gmic.20227 -
Frontiers in Microbiology 2019is an emerging aquatic pathogen causing hemorrhagic septicemia in humans and animals. Probiotic is an effective strategy for controlling enteric infections through...
UNLABELLED
is an emerging aquatic pathogen causing hemorrhagic septicemia in humans and animals. Probiotic is an effective strategy for controlling enteric infections through reducing intestinal colonization by pathogens. Here we report that the consumption of regulated the intestinal innate immune response and decreased the degree of intestinal inflammation damage caused by the in Crucian carp. In this study, we isolated four strains of , named C-11, S-22, L-17 and S-14 from apparently healthy Crucian carp, which exerted a broad-spectrum antimicrobial activity inhibiting both Gram-positive and Gram-negative bacteria especially the fish pathogens. isolates showed typical characteristics by endospore staining, physiological and biochemical test, enzyme activity analysis (amylase, protease, and lipase), and molecular identification. Here, -containing dietary was orally administrated to Crucian carp for 8 weeks before challenge. Immunological parameters and the expression of immune-related genes were measured at 2, 4, 6, 8, and 10 weeks post-administration. The results showed that was found to promote the increase in the phagocytic activities of peripheral blood leukocytes (PBLs) and head kidney leukocytes (HKLs), as well as the increase in interleukin 1β (IL-1β), IL-10 and tumor necrosis factor α (TNF-α) concentration of serum. Lysozyme levels (113.76 U/mL), ACP activity (25.32 U/mL), AKP activity (130.08 U/mL), and SOD activity (240.63 U/mL) were maximum ( < 0.05) in the C-11 treated group at 8 week. Our results showed that Crucian carp fed with the diet containing C-11 and S-22 developed a strong immune response with significantly higher ( < 0.05) levels of IgM in samples of serum, mucus of skin and intestine compared to L-17 and S-14 groups. Moreover, spores appeared to show no toxicity and damage in fish, which could inhabit the gut of Crucian carp. restrained up-regulation of pro-inflammation cytokines (IL-1β, IFN-γ, and TNF-α) mRNA levels in the intestine and head kidney at final stage of administration, and the expression of IL-10 was increased throughout the 10-week trial. infection increased the population of inflammatory cells in the intestinal villi in the controls. In contrast, numerous goblet cells and few inflammatory cells infiltrated the mucosa in the groups after challenge with . Compared with group, could safeguard the integrity of intestinal villi. The highest post-challenge survival rate (75.0%) was recorded in C-11 group. The present data suggest that probiotic act as a potential gut-targeted therapy regimens to protecting fish from pathogenic bacteria infection.
IMPORTANCE
In this work, four strains isolated from apparently healthy Crucian carp, which exhibited a broad-spectrum antibacterial activity especially the fish pathogens. Administration of induced the enhancement of the intestinal innate immune response through reducing intestinal colonization by pathogens. The isolation and characterization would help better understand probiotic can be recognized as an alternative of antimicrobial drugs protecting human and animal health.
PubMed: 31798571
DOI: 10.3389/fmicb.2019.02663 -
BMC Microbiology Jun 2021Aeromonas veronii is a bacterial pathogen in aquaculture, which produces virulence factors to enable it colonize and evade host immune defense. Given that experimental...
BACKGROUND
Aeromonas veronii is a bacterial pathogen in aquaculture, which produces virulence factors to enable it colonize and evade host immune defense. Given that experimental verification of virulence factors is time-consuming and laborious, few virulence factors have been characterized. Moreover, most studies have only focused on single virulence factors, resulting in biased interpretation of the pathogenesis of A. veronii.
RESULTS
In this study, a PPI network at genome-wide scale for A. veronii was first constructed followed by prediction and mapping of virulence factors on the network. When topological characteristics were analyzed, the virulence factors had higher degree and betweenness centrality than other proteins in the network. In particular, the virulence factors tended to interact with each other and were enriched in two network modules. One of the modules mainly consisted of histidine kinases, response regulators, diguanylate cyclases and phosphodiesterases, which play important roles in two-component regulatory systems and the synthesis and degradation of cyclic-diGMP. Construction of the interspecies PPI network between A. veronii and its host Oreochromis niloticus revealed that the virulence factors interacted with homologous proteins in the host. Finally, the structures and interacting sites of the virulence factors during interaction with host proteins were predicted.
CONCLUSIONS
The findings here indicate that the virulence factors probably regulate the virulence of A. veronii by involving in signal transduction pathway and manipulate host biological processes by mimicking and binding competitively to host proteins. Our results give more insight into the pathogenesis of A. veronii and provides important information for designing targeted antibacterial drugs.
Topics: Aeromonas veronii; Animals; Cichlids; Fish Diseases; Genome, Bacterial; Gram-Negative Bacterial Infections; Virulence Factors
PubMed: 34162325
DOI: 10.1186/s12866-021-02261-8 -
Microorganisms Dec 2022This study aimed to evaluate antimicrobial resistance, virulence, and the genetic diversity of isolated from migratory birds from Guangxi Province, Guangdong Province,...
This study aimed to evaluate antimicrobial resistance, virulence, and the genetic diversity of isolated from migratory birds from Guangxi Province, Guangdong Province, Ningxia Hui Autonomous Region, Jiangxi Province, and Inner Mongolia in China. A total of 810 samples were collected, including fresh feces, cloacal swabs, and throat swabs. The collected samples were processed and subjected to bacteriological examination. The resistance to 21 antibiotics was evaluated. A phylogenetic tree was constructed using concatenated ----- sequences. Eight putative virulence factors were identified by PCR and sequencing, and a biofilm formation assay was performed using a modified microtiter plate method. In total, 176 isolates were isolated including , , , and . All isolates showed variable resistance against all 16 tested antibiotic discs, and only one antibiotic had no reference standard. Six kinds of virulence gene markers were discovered, and the detection rates were 46.0% (), 76.1% (), 52.3% (), 4.5% (), 54.0% (), and 64.2% (). These strains were able to form biofilms with distinct magnitudes; 102 were weakly adherent, 14 were moderately adherent, 60 were non-adherent, and none were strongly adherent. Our results suggest that migratory birds carry highly virulent and multidrug-resistant and spread them around the world through migration, which is a potential threat to public health.
PubMed: 36677299
DOI: 10.3390/microorganisms11010007