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PeerJ 2023Tilapia is a primary aquaculture fish in Thailand, but little is known about the occurrence of antimicrobial resistance (AMR) in , spp., and colonizing healthy tilapia...
BACKGROUND
Tilapia is a primary aquaculture fish in Thailand, but little is known about the occurrence of antimicrobial resistance (AMR) in , spp., and colonizing healthy tilapia intended for human consumption and the co-occurrence of these AMR bacteria in the cultivation water.
METHODS
This study determined the phenotype and genotype of AMR, extended-spectrum -lactamase (ESBL) production, and virulence factors of , spp., and isolated from hybrid red tilapia and cultivation water in Thailand. Standard culture methods such as USFDA's BAM or ISO procedures were used for the original isolation, with all isolates confirmed by biochemical tests, serotyping, and species-specific gene detection based on PCR.
RESULTS
A total of 278 isolates consisting of 15 , 188 spp., and 75 isolates were retrieved from a previous study. All isolates of and isolates were resistance to at least one antimicrobial, with 26.7% and 72.3% of the isolates being multidrug resistant (MDR), respectively. All isolates were resistant to ampicillin (100%), followed by oxytetracycline (26.7%), tetracycline (26.7%), trimethoprim (26.7%), and oxolinic acid (20.0%). The predominant resistance genes in were (20.0%), followed by 13.3% of isolates having , , , , and isolates also exhibited a high prevalence of resistance to ampicillin (79.3%), oxolinic acid (75.5%), oxytetracycline (71.8%), chloramphenicol (62.8%), and florfenicol (55.3%). The most common resistance genes in these isolates were (65.4%), (64.9%), (63.8%), and (55.9%). All isolates were susceptible to all antimicrobials tested, while the most common resistance gene was (12.0%). One isolate of was positive for , while all isolates of and isolates were negative for integrons and . None of the bacterial isolates in this study were producing ESBL. The occurrence of (20.0%) in these isolates from tilapia aquaculture may signify a serious occupational and consumer health risk given that colistin is a last resort antimicrobial for treatment of Gram-negative bacteria infections.
CONCLUSIONS
Findings from this study on AMR bacteria in hybrid red tilapia suggest that aquaculture as practiced in Thailand can select for ubiquitous AMR pathogens, mobile genetic elements, and an emerging reservoir of and colistin-resistant bacteria. Resistant and pathogenic bacteria, such as resistance to ampicillin and tetracycline, or MDR circulating in aquaculture, together highlight the public health concerns and foodborne risks of zoonotic pathogens in humans from cultured freshwater fish.
Topics: Animals; Aeromonas hydrophila; Ampicillin; Anti-Bacterial Agents; Colistin; Drug Resistance, Bacterial; Oxolinic Acid; Oxytetracycline; Tetracycline; Tilapia; Virulence Factors
PubMed: 36855429
DOI: 10.7717/peerj.14896 -
Biomolecules Jul 2021The aims of this research were to perform molecular characterization and biofunctional analyses of giant river prawn and genes ( and ) under various stress conditions....
The aims of this research were to perform molecular characterization and biofunctional analyses of giant river prawn and genes ( and ) under various stress conditions. Comparisons of the nucleotide and amino acid sequences of and with those of other species showed the highest similarity scores with crustaceans. Under normal conditions, expression analysis using quantitative real-time RT-PCR (qRT-PCR) indicated that was highly expressed in the gills and testis, and expression was observed in all tissues, with the highest expression in the ovary. The expression patterns of and transcripts under challenge and heat-cold shock conditions were examined in gills, the hepatopancreas and hemocytes, at 0, 3, 6, 12, 24, 48 and 96 h by qRT-PCR. Under bacterial challenge, displayed variable expression patterns in all tissues examined during the tested periods. In contrast, upregulated expression of was quickly observed from 3 to 12 h in the gills and hepatopancreas, whereas obviously significant upregulation of was observed in hemocytes at 12-96 h. Under temperature shock conditions, upregulation of expression was detected in all tested tissues, while expression was quickly upregulated at 3-48 h in all tissues in response to 35 °C conditions, and conditions of 35 and 25 °C stimulated its expression in gills and the hepatopancreas at 12 and 48 h, respectively. Silencing analyses of these two genes were successfully conducted under normal, high-temperature (35 °C) and infection conditions. Overall, knockdown of and effectively induced more rapid and higher mortality than in the PBS control and GFP induction groups in temperature and infectious treatments. Evidence from this study clearly demonstrated the significant functional roles of and , which are crucially involved in cellular stress responses to both temperature and pathogenic bacterial stimuli.
Topics: Aeromonas hydrophila; Animals; Cold-Shock Response; Disease Resistance; Gene Expression Regulation; Gene Knockdown Techniques; HSP40 Heat-Shock Proteins; HSP90 Heat-Shock Proteins; Heat-Shock Response; Palaemonidae; Phylogeny; Temperature
PubMed: 34356657
DOI: 10.3390/biom11071034 -
International Journal of Molecular... Oct 2022CD68 is a highly glycosylated transmembrane glycoprotein that belongs to the lysosome-associated membrane glycoprotein family and is involved in various immune...
CD68 is a highly glycosylated transmembrane glycoprotein that belongs to the lysosome-associated membrane glycoprotein family and is involved in various immune processes. In this study, Megalobrama amblycephala CD68 (MaCD68) was cloned and characterized, and its expression patterns and evolutionary characteristics were analyzed. The coding region of MaCD68 was 987 bp, encoding 328 amino acids, and the predicted protein molecular weight was 34.9 kDa. MaCD68 contained two transmembrane helical structures and 18 predicted N-glycosylation sites. Multiple sequence alignments showed that the MaCD68 protein had high homology with other fish, and their functional sites were also highly conserved. Phylogenetic analysis revealed that MaCD68 and other cypriniformes fish clustered into one branch. Adaptive evolution analysis identified several positively selected sites of teleost CD68 using site and branch-site models, indicating that it was under positive selection pressure during evolution. Quantitative real-time reverse transcription polymerase chain reaction analysis showed that MaCD68 was highly expressed in the head kidney, spleen, and heart. After Aeromonas hydrophila infection, MaCD68 was significantly upregulated in all tested tissues, peaking at 12 h post-infection (hpi) in the kidney and head kidney and at 120 hpi in the liver and spleen, suggesting that MaCD68 participated in the innate immune response of the host against bacterial infection. Immunohistochemical and immunofluorescence analyses also showed that positive signals derived from the MaCD68 protein were further enhanced after bacterial and lipopolysaccharide treatment, which suggested that MaCD68 is involved in the immune response and could be used as a macrophage marker. Biological activity analysis indicated that recombinant MaCD68 (rMaCD68) protein had no agglutination or bactericidal effects on A. hydrophila but did have these effects on Escherichia coli. In conclusion, these results suggest that MaCD68 plays a vital role in the immune response against pathogens, which is helpful in understanding the immune responses and mechanisms of M. amblycephala.
Topics: Animals; Cyprinidae; Fish Diseases; Gram-Negative Bacterial Infections; Phylogeny; Amino Acid Sequence; Cloning, Molecular; Base Sequence; Aeromonas hydrophila; Cypriniformes; Recombinant Proteins; Fish Proteins
PubMed: 36361921
DOI: 10.3390/ijms232113133 -
Molecules (Basel, Switzerland) Mar 2020The bi-enzymatic synthesis of the antiviral drug vidarabine (arabinosyladenine, ara-A), catalyzed by uridine phosphorylase from (UP) and a purine nucleoside...
The bi-enzymatic synthesis of the antiviral drug vidarabine (arabinosyladenine, ara-A), catalyzed by uridine phosphorylase from (UP) and a purine nucleoside phosphorylase from (PNP), was re-designed under continuous-flow conditions. Glyoxyl-agarose and EziG1 (Opal) were used as immobilization carriers for carrying out this preparative biotransformation. Upon setting-up reaction parameters (substrate concentration and molar ratio, temperature, pressure, residence time), 1 g of vidarabine was obtained in 55% isolated yield and >99% purity by simply running the flow reactor for 1 week and then collecting (by filtration) the nucleoside precipitated out of the exiting flow. Taking into account the substrate specificity of UP and PNP, the results obtained pave the way to the use of the UP/PNP-based bioreactor for the preparation of other purine nucleosides.
Topics: Aeromonas hydrophila; Antiviral Agents; Biocatalysis; Bioreactors; Biotransformation; Clostridium perfringens; Enzymes, Immobilized; Glyoxylates; Humans; Protein Engineering; Purine Nucleosides; Purine-Nucleoside Phosphorylase; Sepharose; Substrate Specificity; Vidarabine
PubMed: 32182773
DOI: 10.3390/molecules25051223 -
Water Research May 2024Free-living (FL) and particulate-associated (PA) communities are distinct bacterioplankton lifestyles with different mobility and dissemination routes. Understanding...
Free-living (FL) and particulate-associated (PA) communities are distinct bacterioplankton lifestyles with different mobility and dissemination routes. Understanding spatio-temporal dynamics of PA and FL fractions will allow improvement to wastewater treatment processes including pathogen and AMR bacteria removal. In this study, PA, FL and sediment community composition and antimicrobial resistance gene (ARG; tetW, ermB, sul1, intI1) dynamics were investigated in a full-scale municipal wastewater free-water surface polishing constructed wetland. Taxonomic composition of PA and FL microbial communities shifted towards less diverse communities (Shannon, Chao1) at the CW effluent but retained a distinct fraction-specific composition. Wastewater treatment plant derived PA communities introduced the bulk of AMR load (70 %) into the CW. However, the FL fraction was responsible for exporting over 60 % of the effluent AMR load given its high mobility and the effective immobilization (1-3 log removal) of PA communities. Strong correlations (r>0.8, p < 0.05) were observed between the FL fraction, tetW and emrB dynamics, and amplicon sequence variants (ASVs) of potentially pathogenic taxa, including Bacteroides, Enterobacteriaceae, Aeromonadaceae, and Lachnospiraceae. This study reveals niche differentiation of microbial communities and associated AMR in CWs and shows that free-living bacteria are a primary escape route of pathogenic and ARG load from CWs under low-flow hydraulic conditions.
Topics: Wetlands; Anti-Bacterial Agents; Drug Resistance, Bacterial; Wastewater; Bacteria; Microbiota; Waste Disposal, Fluid
PubMed: 38442607
DOI: 10.1016/j.watres.2024.121408 -
The ISME Journal Nov 2022Flavonoids are stress-inducible metabolites important for plant-microbe interactions. In contrast to their well-known function in initiating rhizobia nodulation in...
Flavonoids are stress-inducible metabolites important for plant-microbe interactions. In contrast to their well-known function in initiating rhizobia nodulation in legumes, little is known about whether and how flavonoids may contribute to plant stress resistance through affecting non-nodulating bacteria. Here we show that flavonoids broadly contribute to the diversity of the Arabidopsis root microbiome and preferentially attract Aeromonadaceae, which included a cultivable Aeromonas sp. H1 that displayed flavonoid-induced chemotaxis with transcriptional enhancement of flagellum biogenesis and suppression of fumarate reduction for smooth swims. Strain H1 showed multiple plant-beneficial traits and enhanced plant dehydration resistance, which required flavonoids but not through a sudden "cry-for-help" upon stress. Strain H1 boosted dehydration-induced HO accumulation in guard cells and stomatal closure, concomitant with synergistic induction of jasmonic acid-related regulators of plant dehydration resistance. These findings revealed a key role of flavonoids, and the underlying mechanism, in mediating plant-microbiome interactions including the bacteria-enhanced plant dehydration resistance.
Topics: Aeromonas; Arabidopsis; Dehydration; Flavonoids; Fumarates; Hydrogen Peroxide; Microbiota; Plant Roots; Plants
PubMed: 35842464
DOI: 10.1038/s41396-022-01288-7 -
International Journal of Molecular... Nov 2021Four chitinases were cloned and characterized from three strains isolated from a mudflat: sp. SK10, sp. SK15, and sp. SK16. In SK10, three genes, Chi18A, Pro2K, and...
Four chitinases were cloned and characterized from three strains isolated from a mudflat: sp. SK10, sp. SK15, and sp. SK16. In SK10, three genes, Chi18A, Pro2K, and Chi19B, were found as a cluster. Chi18A and Chi19B were chitinases, and Pro2K was a metalloprotease. With combinatorial amplification of the genes and analysis of the hydrolysis patterns of substrates, Chi18A and Chi19B were found to be an endochitinase and exochitinase, respectively. Chi18A and Chi19B belonged to the glycosyl hydrolase family 18 (GH18) and GH19, with 869 and 659 amino acids, respectively. Chi18C from SK15 belonged to GH18 with 864 amino acids, and Chi18D from SK16 belonged to GH18 with 664 amino acids. These four chitinases had signal peptides and high molecular masses with one or two chitin-binding domains and, interestingly, preferred alkaline conditions. In the activity staining, their sizes were determined to be 96, 74, 95, and 73 kDa, respectively, corresponding to their expected sizes. Purified Chi18C and Chi18D after pET expression produced ,'-diacetylchitobiose as the main product in hydrolyzing chitooligosaccharides and colloidal chitin. These results suggest that Chi18A, Chi18C, and Chi18D are endochitinases, that Chi19B is an exochitinase, and that these chitinases can be effectively used for hydrolyzing natural chitinous sources.
Topics: Aeromonas; Bacterial Proteins; Betaproteobacteria; Chitin; Chitinases; Geologic Sediments; Hydrolysis; Phylogeny
PubMed: 34884628
DOI: 10.3390/ijms222312822 -
Microbiology Spectrum Jun 2022KPC-24, different from KPC-2 by a single amino acid alteration at codon 6 (R6P), was initially discovered in Klebsiella pneumoniae in Chile. Here, we reported...
KPC-24, different from KPC-2 by a single amino acid alteration at codon 6 (R6P), was initially discovered in Klebsiella pneumoniae in Chile. Here, we reported KPC-24-producing Aeromonas veronii isolates from hospital sewage in China. The was cloned and the MICs were tested against β-lactams antimicrobial agents. KPC-24 exhibited a β-lactam susceptibility profile similar to that of KPC-2. Whole-genome sequencing and analysis revealed that was located within a Tn-related region on an IncP-6 plasmid. Our study described a variant of K. pneumoniae carbapenemase (KPC), KPC-24, from two A. veronii strains isolated from hospital sewage, in which antibiotics, biocides, pharmaceuticals, and heavy metals may supply an appropriate condition for the evolution of carbapenemases. Some variants exhibited stronger hydrolysis activity to antibiotics and gave rise to a major public health concern. More seriously, species are prevalent in aquatic environments and, thus, may act as a suitable vector for antibiotics-resistance genes and foster the transmission of resistance. We should attach importance to surveying the evolution and transmission of antibiotics-resistance genes.
Topics: Aeromonas veronii; Anti-Bacterial Agents; Bacterial Proteins; Hospitals; Humans; Klebsiella Infections; Klebsiella pneumoniae; Microbial Sensitivity Tests; Plasmids; Sewage; beta-Lactamases
PubMed: 35546572
DOI: 10.1128/spectrum.00555-22 -
Microbiology Spectrum Dec 2023The emergence and spread of carbapenemase-producing organisms (CPOs) represent a global health threat because they are associated with limited treatment options and poor...
Municipal wastewater monitoring revealed the predominance of genes with diverse variants among carbapenemase-producing organisms: high occurrence and persistence of harboring the new variant .
The emergence and spread of carbapenemase-producing organisms (CPOs) represent a global health threat because they are associated with limited treatment options and poor clinical outcomes. Wastewater is considered a hotspot for the evolution and dissemination of antimicrobial resistance. Thus, analyses of municipal wastewater are critical for understanding the circulation of these CPOs and carbapenemase genes in local communities, which remains scarcely known in Japan. This study resulted in several key observations: (i) the vast majority of genes, including six new variants, and less frequent genes were carbapenemase genes encountered exclusively in wastewater influent; (ii) the most dominant CPO species were spp., in which a remarkable diversity of new sequence types was observed; and (iii) CPOs were detected from combined sewer wastewater, but not from separate sewer wastewater, suggesting that the load of CPOs from unrecognized environmental sources could greatly contribute to their detection in influent wastewater.
Topics: Aeromonas caviae; Wastewater; beta-Lactamases; Bacterial Proteins; Microbial Sensitivity Tests; Anti-Bacterial Agents
PubMed: 37811969
DOI: 10.1128/spectrum.02188-23 -
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